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author | Thomas Voss <mail@thomasvoss.com> | 2024-11-27 20:54:24 +0100 |
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committer | Thomas Voss <mail@thomasvoss.com> | 2024-11-27 20:54:24 +0100 |
commit | 4bfd864f10b68b71482b35c818559068ef8d5797 (patch) | |
tree | e3989f47a7994642eb325063d46e8f08ffa681dc /doc/rfc/rfc869.txt | |
parent | ea76e11061bda059ae9f9ad130a9895cc85607db (diff) |
doc: Add RFC documents
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diff --git a/doc/rfc/rfc869.txt b/doc/rfc/rfc869.txt new file mode 100644 index 0000000..9bcb871 --- /dev/null +++ b/doc/rfc/rfc869.txt @@ -0,0 +1,4171 @@ + + + + + RFC - 869 + + + + + + + A Host Monitoring Protocol + + + + + + + + + + + + + + + + Robert M. Hinden + + + + + + BBN Communications Corporation + + + + + + December 1983 + + + + + + + + + + + + + + +RFC-869 December 1983 + + + + Table of Contents + + + + + +1 Introduction.......................................... 1 + +2 General Description................................... 3 + +3 Relationship to Other Protocols....................... 6 + +4 Protocol Operation.................................... 7 + +5 Header Formats....................................... 12 +5.1 IP Headers......................................... 12 +5.2 HMP Header......................................... 13 + +6 HMP Monitoring Center Message Formats................ 16 +6.1 Message Type 100: Polling Message.................. 16 +6.2 Message Type 101: Error in Poll.................... 18 +6.3 Message Type 102: Control acknowledgment........... 20 + +A Appendix A - IMP Monitoring.......................... 21 +A.1 Message Type 1: IMP Trap........................... 21 +A.2 Message Type 2: IMP status......................... 24 +A.3 Message Type 3: IMP Modem Throughput............... 29 +A.4 Message Type 4: IMP Host Throughput................ 32 + +B Appendix B - TAC Monitoring.......................... 35 +B.1 Message Type 1: TAC Trap Message................... 35 +B.2 Message Type 2: TAC Status......................... 38 +B.3 Message Type 3: TAC Throughput..................... 42 + +C Appendix C - Gateway Monitoring...................... 47 +C.1 Gateway Parameters................................. 47 +C.2 Message Type 1: Gateway Trap....................... 48 +C.3 Message Type 2: Gateway Status..................... 51 +C.4 Message Type 3: Gateway Throughput................. 58 +C.5 Message Type 4: Gateway Host Traffic Matrix........ 64 +C.6 Message Type 6: Gateway Routing.................... 67 + + + + + + + + + + + -i- + + +RFC-869 December 1983 +Replaces IEN-197 + + + A Host Monitoring Protocol + + + + + +1 Introduction + + + The Host Monitoring Protocol (HMP) is used to collect + +information from hosts in various networks. A host is + +defined as an addressable Internet entity that can send and + +receive messages; this includes hosts such as server hosts, + +personal work stations, terminal concentrators, packet switches, + +and gateways. At present the Host Monitoring Protocol is being + +used to collect information from Internet Gateways and TACs, and + +implementations are being designed for other hosts. It is + +designed to monitor hosts spread over the internet as well as + +hosts in a single network. + + + This document is organized into three parts. Section 2 and + +3 contains a general description of the Host Monitoring protocol + +and its relationship to other protocols. Section 4 describes + +how it operates. Section 5 and 6 contain the descriptions and + +formats of the HMP messages. These are followed by appendices + +containing the formats of messages sent by some of the hosts that + +use the HMP to collect their monitoring information. These + +appendicies included as examples only and are not part of the HMP + +protocol. + + + + + -1- + + +RFC-869 December 1983 + + + + This document replaces the previous HMP document "IEN-197, A + +Host Monitoring Protocol." + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -2- + + +RFC-869 December 1983 + + + +2 General Description + + + The Host Monitoring Protocol is a transaction-oriented + +(i.e., connection-less) transport protocol. It was designed to + +facilitate certain simple interactions between two internet + +entities, one of which may be considered to be "monitoring" the + +other. (In discussing the protocol we will sometimes speak of a + +"monitoring host" and a "monitored entity".) HMP was intended to + +be a useful transport protocol for applications that involve any + +or all of the following three different kinds of interactions: + + + - The monitored entity sometimes needs to send unsolicited + datagrams to the monitoring host. The monitoring host + should be able to tell when messages from the monitored + entity have been lost in transit, and it should be able to + determine the order in which the messages were sent, but the + application does not require that all messages be received + or that they be received strictly in the same sequence in + which they were sent. + + - The monitoring host needs to gather data from the monitored + entity by using a query-response protocol at the application + level. It is important to be able to determine which query + is being answered by a particular response, and to determine + whether successive responses are duplicates of previous + ones. + + - The monitoring host must be able to initiate certain control + functions in the monitored entity, possibly including the + setting of parameters in the monitored entity. The + monitoring host needs to know if the control function has + been carried out. + + + In addition, we assume that a given monitoring host may be + +monitoring several different types of entities simultaneously, + +and may be gathering several different types of data from a given + + + + -3- + + +RFC-869 December 1983 + + + +type of monitored entity. Several different monitoring hosts may + +be monitoring a given entity, and several processes on the same + +host may even be monitoring the same entity. + + + Messages from the monitoring host to the monitored entity + +are called "polls". They need to contain enough information to + +allow the monitored entity to make the following determinations: + + + - The monitored entity must be able to determine that this + message is in fact a poll from a monitoring host. The + "system type," "message type," and "password" fields in the + HMP header have been defined to meet this need. + + - The monitored entity may need to be able to identify the + particular process on the monitoring host that sent this + poll, so it can send its response back to the right process. + The "port number" field in the HMP header has been defined + to meet this need. + + - The monitored entity must be able to indicate to the + monitoring host, in its response, precisely which query is + being answered by a particular response. The "sequence + number field" has been defined to meet this need. + + - The monitored entity must be able to determine just what + kind of action the monitoring host is requesting. That is, + the HMP transport protocol must provide some way of + multiplexing and demultiplexing the various higher-level + applications which use it. The "R-message type" and "R- + subtype" fields of the polling message have been defined to + meet this need. + + + Messages from the monitored entity to the monitoring host + +need to contain enough information to enable the monitoring host + +to make the following determination: + + + - The monitoring host must be able to route this message to + the correct process. The "port number" field meets this + need. + + + -4- + + +RFC-869 December 1983 + + + + - The monitoring host must be able to match up received + messages with the polls, if any, that elicited them. The + "returned sequence number" field in the HMP header has been + defined to meet this need. + + - The monitoring host must be able to determine which higher + level application should receive a particular message. The + "system type" and "message type" fields are used for this + purpose. + + - The monitoring host must be able to determine whether some + messages of a given type were lost in transit, and whether + messages have arrived out of sequence. Although this + function, strictly speaking, belongs to the application and + not to the transport layer, the HMP header contains a + "sequence number" for this purpose. + + + In addition, a simple one's complement checksum is provided + +in the HMP header to detect data corruption during transmission. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -5- + + +RFC-869 December 1983 + + + +3 Relationship to Other Protocols + + + The Host Monitoring Protocol is a transport protocol + +designed to fit into the layered internet protocol environment. + +It operates on top of the Internet/ICMP protocol and under + +applications that require its services. This relationship is + +illustrated in the following diagram: + + + +------+ +------+ +-------+ +------+ + |TELNET| ...| FTP | |GATEWAY| ... | TAC | Application Layer + +------+ +------+ +-------+ +------+ + | | | | + | | | | + |__________| |_____________| + | | + +------+ +-------+ + | TCP | | HMP | Transport Layer + +------+ +-------+ + | | + | | + +-------------------------------------+ + | Internet Protocol & ICMP | Internetwork Layer + +-------------------------------------+ + | + +------------------------+ + | Local Network Protocol | Network Layer + +------------------------+ + + +If internetwork services are not required it should be possible + +to run the HMP without an Internetwork layer. As long as HMPs' + +service requirnments (addressing, protocol demultiplexing, and + +occasional delivery) are met it should run over a variety of + +protocols. + + + + + + + + -6- + + +RFC-869 December 1983 + + + +4 Protocol Operation + + + The HMP is built around the idea that most of the + +intelligence needed to monitor a host should reside in a + +monitoring center, not in the host. The host should be required + +only to collect data and send it to the monitoring center, either + +spontaneously or on request from the monitoring center. The host + +is not responsible for insuring that the data arrives reliably + +(except that it checksums the data); instead, the monitoring + +center is responsible for ensuring that the data it requests is + +received correctly. + + + Consequently, the HMP is based on polling hosts for + +messages. When the monitoring center requires a particular type + +of data (e.g., throughput data), it sends a poll to the host + +requesting that type of report. The host, upon receiving the + +poll, responds with its latest set of collected data. If the + +host finds that the poll is incorrect (e.g., if the poll was for + +throughput data and the host is not collecting throughput data), + +it responds with an error message. The monitoring center waits a + +reasonable length of time for the host to answer its poll. If no + +response is received, it sends another poll for the same data. + +In this way, if either a poll or the response is lost, the + +correct data is still collected. + + + + + + + -7- + + +RFC-869 December 1983 + + + + The HMP is used to collect three different classes of data: + + + o Spontaneous Events (or Traps) + + o Current status + + o Statistical data collected over time + + +These classes of data allow a host to send data in a manner best + +suited to the data. For instance, the host may quickly inform + +the monitoring center that a particular event has happened by + +sending a trap message, while the monitoring center is reliably + +collecting the host's throughput and accounting data. + + + Traps report spontaneous events, as they occur, to the + +monitoring center. In order to insure their prompt delivery, the + +traps are sent as datagrams with no reliability mechanisms + +(except checksums) such as acknowledgments and retransmissions. + +Trap messages usually contain an identifier to indicate which + +event is being reported, the local time in the host that the + +event occured, and data pertinent to the event. The data portion + +is intended to be host and event specific. + + + Status information, the second type of data collected by the + +Host Monitoring Protocol describes the current state of the host. + +Status information is useful at one point, but it does not have + +to be collected cumulatively over a certain period of time. Only + +the latest status is of interest; old status provides no useful + +information. The monitoring center collects status information + + + -8- + + +RFC-869 December 1983 + + + +by sending a poll for status to a host. Upon receiving the poll, + +the host responds with its latest status information, always + +creating a new status message. If the monitoring center does not + +receive a response to its poll, it sends another poll. The + +monitoring center can decide if the host is up or down based on + +whether the host responds to its polls. + + + The third type of data collected by the HMP is statistical + +data. These are measurements taken over time, such as the number + +of packets sent or received by a host and the count of packets + +dropped for a particular reason. It is important that none of + +this type of data be lost. Statistical data is collected in a + +host over a time interval. When the collection time interval + +expires, the current data is copied to another area, and the + +counters are cleared. The copied data is sent to the monitoring + +center when the host receives a poll requesting statistical + +information. If another poll is received before the collection + +time interval has expired, the data in the buffer is sent again. + +The monitoring center can detect duplicate messages by using the + +sequence number in the header of the message, since each type of + +statistical data has its own sequence number counter. + + + The collection frequency for statistics messages from a + +particular host must be relatively long compared to the average + +round trip message time between the monitoring center and that + +host inorder to allow the monitoring center to re-poll if it does + + + -9- + + +RFC-869 December 1983 + + + +not receive an answer. With this restriction, it should be + +possible to avoid missing any statistics messages. Each + +statistics message contains a field giving the local time when + +the data was collected and the time at which the message was + +sent. This information allows the monitoring center to schedule + +when it sends a poll so that the poll arrives near the beginning + +of each collection period. This ensures that if a message is + +lost, the monitoring center will have sufficient time to poll + +again for the statistics message for that period. + + + The HMP also includes a provision to send data to and read + +parameters in hosts. The data may be used to set switches or + +interval timers used to control measurements in a host, or to + +control the host itself (e.g. a restart switch). The format of + +the data and parameters is host specific. + + + To send data to a host, the monitoring center sends the host + +a poll for a control-acknowledgment message. This poll message + +includes the type of the data and the data being sent. When the + +host receives this poll, it processes the data and responds with + +a control-acknowledgment message. + + + To read parameters in a host, the monitoring center will + +send a poll for parameters to the host. This poll includes the + +type of the parameters being read. When the host receives this + +poll, it will send the parameters of the requested type to the + + + + -10- + + +RFC-869 December 1983 + + + +monitoring center in a parameters message. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -11- + + +RFC-869 December 1983 + + + +5 Header Formats + + + Host Monitor Protocol messages have the following format: + + +----------------+ + | Local Network | + | Header(s) | + +----------------+ + | IP header | + +----------------+ + | HMP | + | Header | + | | + +----------------+ + | D | + | A | + | T | + | A | + +----------------+ + | Padding | + +----------------+ + + + + + +5.1 IP Headers + +HMP messages are sent using the version 4 IP header as described +in RFC-791 "Internet Protocol." The HMP protocol number is 20 +(decimal). The time to live field should be set to a reasonable +value for the hosts being monitored. + +All other fields should be set as specified in RFC-791. + + + + + + + + + + + + + + + + + -12- + + +RFC-869 December 1983 + + + +5.2 HMP Header + +The HMP header format is: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | System Type | Message Type | + +---------------+---------------+ + 1 | Port Number | Control Flag | + +---------------+---------------+ + 2 | Sequence Number | + +---------------+---------------+ + 3 | Password or Returned Seq. # | + +---------------+---------------+ + 4 | One's Complement Checksum | + +---------------+---------------+ + +HMP FIELDS: + +System Type +Message Type + + The combination of system type and message type determines + the format of the data in the monitoring message. + + The system types which have been defined are: + + + System Type | Meaning + ----------------+----------------- + 1 | Monitoring Host + 2 | IMP + 3 | TAC + 4 | Gateway + 5 | SIMP + 6 | BBN VAX/C70 TCP + 7 | PAD + 8 | Reserved + 9 | TIU + 10 | FEP + 11 | Cronus Host + 12 | Cronus MCS + + + + + + + + + -13- + + +RFC-869 December 1983 + + + + Message types are defined and used for each system type + according to the needs of that system. The message types + currently defined are: + + + + Type | Description + ----------+-------------------------- + | + 1 | Trap + 2 | Status + 3 | Thruput + 4 | HTM - Host Traffic Matrix + 5 | Parameters + 6 | Routing + 7 | Call Accounting + | + 100 | Poll + 101 | Error + 102 | Control Acknowledgment + + + + +Port Number + + This field can be used to multiplex similar messages to/from + different processes in one host. It is currently unused. + +Control Flag + + This field is used to pass control information. Currently + Bit 15 is defined as the "More bit" which is used in a + message in responce to a poll to indicate that there is more + data to poll for. + +Sequence Number + + Every message contains a sequence number. The sequence + number is incremented when each new message of that type is + sent. + +Password or Returned Sequence Number + + The Password field of a polling message from an monitoring + center contains a password to verify that the monitoring + center is allowed to gather information. Responses to + polling messages copy the Sequence Number from the + polling message and return it in this field for + + + -14- + + +RFC-869 December 1983 + + + + identification and round-trip time calculations. + +Checksum + + The Checksum field is the one's complement of the one's + complement sum of all the 16-bit words in the header and + data area. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -15- + + +RFC-869 December 1983 + + + +6 HMP Monitoring Center Message Formats + +6.1 Message Type 100: Polling Message + +Description + + The monitoring center will send polls to the hosts it is + monitoring to collect their monitoring data. When the host + receives a poll it will return a message of the type + requested. It will only answer a poll with the correct + system type and password and will return an error message + (Message Type 101) if it receives a poll for the wrong + system type or an unsupported message type. + + The Poll message includes a facility to send data to a + monitored host. The poll message to send data consists of a + poll for a Control Acknowledgment message (type 102) + followed by the data. The R-Subtype specifies the type of + the data that is being sent. When the monitored host + receives a Poll for a Control acknowledgment, it processes + the data, and then responds with an Control acknowledgment + message. If the monitored host can not process the data, it + should respond with an error message. + + A poll to read parameters consists a poll for a Parameters + message. The R-Subtype specifies the type of parameters + being read. When the monitored host receives a poll for a + Parameters message, it responds with a Parameters message + containing the requested information. + + A polling message has the following form: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | R-Message Type| R-Subtype | + +---------------+---------------+ + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + 1 | Data | + + + + 2 | | + + + + . . + . . + n | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + + + -16- + + +RFC-869 December 1983 + + + +HMP FIELDS + +System Type + + The type of machine being polled. + +Message Type + + Polling Message = 100 + +Port Number + + Unused + +Control Flag + + Unused + +Sequence Number + + The sequence number identifies the polling request. The + Monitoring Center will maintain separate sequence numbers + for each host it monitors. This sequence number is returned + in the response to a poll and the monitoring center will use + this information to associate polls with their responses and + to determine round trip times. + +Password + + The monitoring password. + +POLL FIELDS + +R-Message Type + + The message type requested. + +R-Subtype + + This field is used when sending data and reading parameters + and it specifies the type of the data being sent or + parameters being read. + +Data + + When the poll is requesting a Control Acknowledgment + message, data is included in the poll message. A poll for + any other type of message does not include any data . The + contents of the data is host specific. + + + -17- + + +RFC-869 December 1983 + + + +6.2 Message Type 101: Error in Poll + +Description + + This message is sent in response to a faulty poll and + specifies the nature of the error. + + An error message has the following form: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | Error Type | + +---------------+---------------+ + 1 | R-Message Type| R-Subtype | + +---------------+---------------+ + +HMP FIELDS + +System Type + + The type of machine sending message. + +Message Type + + Error Message = 101 + +Port Number + + Unused + +Control Flag + + Unused + +Sequence Number + + A 16 bit number incremented each time an error message is + sent. + +Returned Sequence Number + + The Sequence Number of the polling message which caused the + error. + + + + + + + + -18- + + +RFC-869 December 1983 + + + +ERROR MESSAGE FIELDS + +Error Type + + This field specifies the nature of the error in the poll. + The following error types have been defined. + + + 1 = Reason unspecified. + 2 = Bad R-Message Type. + 3 = Bad R-Subtype. + 4 = Unknown parameter + 5 = Invalid parameter value + 6 = Invalid parameter/value format + 7 = Machine in Loader + +R-Message Type +R-Subtype + + These fields identify the poll request in error. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -19- + + +RFC-869 December 1983 + + + +6.3 Message Type 102: Control acknowledgment + +Description + + This message is sent in response to a poll for this type of + message. It is used to acknowledge poll messages that are + used to set parameters in the monitored host. + + The Control acknowledgment has no fields other than the HMP + header. + +HMP FIELDS + +System Type + + The type of the system sending the message. + +Message Type + + Control acknowledgment = 102 + +Port Number + + Unused + +Control Flag + + Unused + +Sequence Number + + A 16 bit number incremented each time a Control + acknowledgment message is sent. + +Returned Sequence Number + + The Sequence Number of the polling message which requested + this message. + + + + + + + + + + + + + + -20- + + +RFC-869 December 1983 + + + +A Appendix A - IMP Monitoring + +A.1 Message Type 1: IMP Trap + +Description + + When a trap occurs, it is buffered in the IMP and sent as + soon as possible. Trap messages are unsolicited. If traps + happen in close sequence, several traps may be sent in one + message. + + Through the use of sequence numbers, it will be possible to + determine how many traps are being lost. If it is + discovered that many are lost, a polling scheme might be + implemented for traps. + + A IMP trap message has the following form: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | # of traps lost | + +---------------+---------------+ + 1 : first : + . : trap : + . : data : + . +---------------+---------------+ + . : additional : + . : trap : + . : data : + +---------------+---------------+ + + +HMP Fields + +System Type + + IMP = 2 + +Message Type + + IMP Trap Message = 1 + +Port Number + + Unused + + + + + + -21- + + +RFC-869 December 1983 + + + +Control Flag + + Unused + +Password + + Unused + +Sequence Number + + A 16 bit number incremented each time a trap message is sent + so that the HM can order the received trap messages and + detect missed messages. + +IMP TRAP FIELDS + +# of traps lost + + Under certain conditions, an IMP may overflow its internal + trap buffers and be unable to save traps to send. This + counter keeps track of such occurrences. + +Trap Reports + + There can be several blocks of trap data in each message. + The format for each such block is below. + + + + +---------------+---------------+ + | Size | + +---------------+---------------+ + | Time | + +---------------+---------------+ + | Trap ID | + +---------------+---------------+ + : Trap : + : Data : + +---------------+---------------+ + + + Size + + Size is the number of 16 bit words in the trap, not counting + the size field. + + Time + + The time (in 640 ms. units) at which the trap occurred. + + + -22- + + +RFC-869 December 1983 + + + + This field is used to sequence the traps in a message and + associate groups of traps. + + Trap ID + + This is usually the program counter at the trap. The ID + identifies the trap, and does not have to be a program + counter, provided it uniquely identifies the trap. + + Trap Data + + The IMP returns data giving more information about the trap. + There are usually two entries: the values in the accumulator + and the index register at the occurrence of the trap. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -23- + + +RFC-869 December 1983 + + + +A.2 Message Type 2: IMP status + +Description + + The status message gives a quick summary of the state of the + IMP. Status of the most important features of the IMP are + reported as well as the current configuration of the + machine. + + The format of the status message is as follows: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | Software Version Number | + +---------------+---------------+ + | Last Trap Message | + +---------------+---------------+ + | Max # Hosts | Max # Modems | + +---------------+---------------+ + | Max # Channels| Max # IMPs | + +---------------+---------------+ + | Package bits 0-15. | + +---------------+---------------+ + 5 | Package bits 16.-31. | + +---------------+---------------+ + | | + + Crash + + | | + + Data + + | | + +---------------+---------------+ + | Anomalies | + +---------------+---------------+ + 10 | Free Pool | S+F Pool | + +---------------+---------------+ + |Reassembly Pool| Allocated Pool| + +---------------+---------------+ + | HIHD0 | HIHD1 | HIHD2 | HIHD3 | + . +---------------+---------------+ + . : HIHD4 | ............... : + . +---------------+---------------+ + (cont.) + + + + + + + + + -24- + + +RFC-869 December 1983 + + + + + + Imp Status (cont.) + + . +---------------+---------------+ + . | Modem | + . + State + + . | Data | + . +---------------+---------------+ + . : Modem State : + . : Data...... : + +---------------+---------------+ + + + +HMP FIELDS + +System Type + + IMP = 2 + +Message Type + + IMP status message = 2 + +Port Number + + Unused + +Control Flag + + Unused + +Sequence Number + + A 16 bit number incremented each time a status message is + sent. + +Password + + The password contains the sequence number of the polling + message to which this message responds. + +IMP STATUS FIELDS + +Software Version Number + + The IMP version number. + + + + -25- + + +RFC-869 December 1983 + + + +Last Trap Message + + Contains the sequence number of the last trap message sent + to the HM. This will allow the HM to detect how many trap + messages are being lost. + +Hosts + + The number of configured hosts in this system. + +Modems + + The number of configured modems in this system. + +Channels + + The maximum possible number of IMP-IMP channels in this + system. + +IMPs + + The maximum possible number of IMPs in this system. + +Package Bits + + This is a bit encoded word that reports the set of packages + currently loaded in the system. The table below defines the + bits. + + + + + + + + + + + + + + + + + + + + + + + + -26- + + +RFC-869 December 1983 + + + + + Bit Package + (octal) + (1st Word) + 1 VDH + 2 Logical address tables + 4 Mezmode + 10 Cumulative Statistics + 20 Trace + 40 TTY + 100 DDT + 200 HDLC + 400 HDH + 1000 Cassette Writer + 2000 Propagation Delay Measurement + 4000 X25 + 10000 Profile Measurements + 20000 Self Authenticating Password + 40000 Host traffic Matrix + 100000 Experimental/Special + + (2nd Word) + 1 End-to-end Statistics + 2 Store and Forward statistics + +Crash Data + + Crash data reports the circumstances surrounding an + unexpected crash. The first word reports the location of + the crash and the following two are the contents of the + accumulator and index registers. + +Anomalies + + Anomalies is a collection of bit flags that indicate the + state of various switches or processes in the IMP. These + are very machine dependent and only a representative + sampling of bits is listed below. + + Bit Meaning + (octal) + 20 Override ON + 200 Trace ON + 1000 Statistics ON + 2000 Message Generator ON + 4000 Packet Trace ON + 10000 Host Data Checksum is BAD + 20000 Reload Location SET + + + + -27- + + +RFC-869 December 1983 + + + +Buffer Pool Counts + + These are four bytes of counters indicating the current + usage of buffers in the IMP. The four counters are: free + buffers, store-and-forward buffers, reassembly buffers and + allocated buffers. + +HIHD0 - HIHDn + + Each four bit HIHD field gives the state of the + corresponding host. + + Value Meaning + 0 UP + 1 ready line down + 2 tardy + 3 non-existent + + + +Modem State Data + + Modem state data contains six fields of data distributed + over four words. The first field (4 bits) indicates the + line speed; the second field (4 bits) is the number of the + modem that is used by the neighboring IMP on this line; the + third field (8 bits) is the number of line protocol ticks + covered by this report; the fourth (1 bit) indicates line + down(1) or up(0); the fifth (7 bits) is the IMP number of + neighbor IMP on the line; and the sixth (8 bits) is a count + of missed protocol packets over the interval specified in + the third field. + + + + + + + + + + + + + + + + + + + + -28- + + +RFC-869 December 1983 + + + +A.3 Message Type 3: IMP Modem Throughput + +Description + + The modem throughput message reports traffic statistics for + each modem in the system. The IMP will collect these data at + regular intervals and save them awaiting a poll from the HM. + If a period is missed by the HM, the new results simply + overwrite the old. Two time stamps bracket the collection + interval (data-time and prev-time) and are an indicator of + missed reports. In addition, mess-time indicates the time + at which the message was sent. + + The modem throughput message will accommodate up to fourteen + modems in one packet. A provision is made to split this + into multiple packets by including a modem number for the + first entry in the packet. This field is not immediately + useful, but if machine sizes grow beyond fourteen modems or + if modem statistics become more detailed and use more than + three words per modem, this can be used to keep the message + within a single ARPANET packet. + + The format of the modem throughput message is as follows: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | Mess-Time | + +---------------+---------------+ + | Software Version Number | + +---------------+---------------+ + | Data-Time | + +---------------+---------------+ + | Prev-Time | + +---------------+---------------+ + | Total Modems | This Modem | + +---------------+---------------+ + 5 | | + . + modem + + . | | + . + throughput + + . | | + . +---------------+---------------+ + . : modem : + . : : + . : throughput : + +---------------+---------------+ + + + + + -29- + + +RFC-869 December 1983 + + + +HMP FIELDS + + +System Type + + IMP = 2 + +Message Type + + IMP Modem Throughput message = 3 + +Port Number + + Unused + +Control Flag + + Unused + +Sequence Number + + A 16 bit number incremented at each collection interval + (i.e. when a new throughput message is assembled). The HM + will be able to detect lost or duplicate messages by + checking the sequence numbers. + +Password + + The password contains the sequence number of the polling + message to which this message responds. + +IMP MODEM THROUGHPUT FIELDS + +Mess-time + + The time (in 640ms. units) at which the message was sent to + the HM. + +Software Version Number + + The IMP version number. + +Data-Time + + Data-time is the time (in 640ms. units) when this set of + data was collected. (See Description.) + + + + + + -30- + + +RFC-869 December 1983 + + + +Prev-Time + + Prev-time is the time (in 640 ms. units) of the previous + collection of data (and therefore, is the time when the data + in this message began accumulating.) + +Total Modems + + This is the number of modems in the system. + +This Modem + + This Modem is the number of the first modem reported in this + message. Large systems that are unable to fit all their + modem reports into a single packet may use this field to + separate their message into smaller chunks to take advantage + of single packet message efficiencies. + +Modem Throughput + + Modem throughput consists of three words of data + reporting packets and words output on each modem. The + first word counts packets output and the following two + count word throughput. The double precision words are + arranged high order first. (Note also that messages from + Honeywell type machines (316s, 516s and C30s) use a fifteen + bit low order word.) The first block reports output on the + modem specified by "This Modem". The following blocks + report on consecutive modems. + + + + + + + + + + + + + + + + + + + + + + + -31- + + +RFC-869 December 1983 + + + +A.4 Message Type 4: IMP Host Throughput + +Description + + The host throughput message reports traffic statistics for + each host in the system. The IMP will collect these data at + regular intervals and save them awaiting a poll from the HM. + If a period is missed by the HM, the new results simply + overwrite the old. Two time stamps bracket the collection + interval (data-time and prev-time) and are an indicator of + missed reports. In addition, mess-time indicates the time + at which the message was sent. + + The host throughput format will hold only three hosts if + packet boundaries are to be respected. A provision is made + to split this into multiple packets by including a host + number for the first entry in the packet. + + The format of the host throughput message is as follows: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | Mess-Time | + +---------------+---------------+ + | Software Version Number | + +---------------+---------------+ + | Data-Time | + +---------------+---------------+ + | Prev-Time | + +---------------+---------------+ + | Total Hosts | This Host | + +---------------+---------------+ + 5 : host : + . : throughput : + +---------------+---------------+ + +HMP FIELDS + +System Type + + IMP = 2 + +Message Type + + IMP host Throughput message = 4 + + + + + + -32- + + +RFC-869 December 1983 + + + +Port Number + + Unused + +Control Flag + + Unused + +Sequence Number + + A 16 bit number incremented at each collection interval + (i.e. when a new throughput message is assembled). The HM + will be able to detect lost or duplicate messages by + checking the sequence numbers. + +Password + + The password contains the sequence number of the polling + message to which this message responds. + +IMP HOST THROUGHPUT FIELDS + +Mess-time + + The time (in 640ms. units) at which the message was sent to + the HM. + +Software Version Number + + The IMP version number. + +Data-Time + + Data-time is the time (in 640ms. units) when this set of + data was collected. (See Description.) + +Prev-Time + + Prev-time is the time (in 640 ms. units) of the previous + collection of data (and therefore, is the time when the data + in this message began accumulating.) + +Total Hosts + + The total number of hosts in this system. + +This Host + + This host is the number of the first host reported in this + + + -33- + + +RFC-869 December 1983 + + + + message. Large systems that are unable to fit all their + host reports into a single packet may use this field to + separate their message into smaller chunks to take advantage + of single packet message efficiencies. + +Host Throughput + + Each host throughput block consists of eight words in the + following format: + + +---------------+---------------+ + | messages to network | + +---------------+---------------+ + | messages from network | + +---------------+---------------+ + | packets to net | + +---------------+---------------+ + | packets from net | + +---------------+---------------+ + | messages to local | + +---------------+---------------+ + | messages from local | + +---------------+---------------+ + | packets to local | + +---------------+---------------+ + | packets from local | + +---------------+---------------+ + + Each host throughput message will contain several blocks of + data. The first block will contain data for the host + specified in First Host Number. Following blocks will + contain data for consecutive hosts. All counters are single + precision. + + + + + + + + + + + + + + + + + + + -34- + + +RFC-869 December 1983 + + + +B Appendix B - TAC Monitoring + +B.1 Message Type 1: TAC Trap Message + +Description + + When a trap occurs, it is buffered in the TAC and sent as + soon as possible. Trap messages are unsolicited. If traps + happen in close sequence, several traps may be sent in one + message. + + Through the use of sequence numbers, it will be possible to + determine how many traps are being lost. If it is + discovered that many are lost, a polling scheme might be + implemented for traps. + + A TAC trap message has the following form: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | Version # | + +---------------+---------------+ + 1 : first : + . : trap : + . : data : + . +---------------+---------------+ + . : additional : + . : trap : + . : data : + +---------------+---------------+ + + +HMP FIELDS + +System Type + + TAC = 3 + +Message Type + + TAC Trap Message = 1 + +Port Number + + Unused + + + + + + -35- + + +RFC-869 December 1983 + + + +Control Flag + + Unused + +Password or Returned Sequence Number + + Unused + +Sequence Number + + A 16 bit number incremented each time a trap message is sent + so that the HM can order the received trap messages and + detect missed messages. + +TAC TRAP FIELDS + +Version # + + The version # of the TAC Software. + +Trap Reports + + There can be several blocks of trap data in each message. + + The format of the trap data is as follows: + + + +---------------+---------------+ + | Size | + +---------------+---------------+ + | Time | + +---------------+---------------+ + | Trap ID | + +---------------+---------------+ + : Trap : + : Data : + +---------------+---------------+ + | Count | + +-------------------------------+ + + Size + + Size is the number of 16 bit words in the trap, not counting + the size field. + + Time + + The time (in 640ms. units) at which the trap occurred. This + field is used to sequence the traps in a message and + + + -36- + + +RFC-869 December 1983 + + + + associate groups of traps. + + Trap ID + + This is (usually) the program counter at the trap. The ID + identifies the trap, and does not have to be a program + counter, provided that it uniquely identifies the trap. + + Trap Data + + The TAC returns data giving more information about the trap. + There are usually two entries: the values in the accumulator + and the index register at the occurrence of the trap. + + Count + + The TAC Counts repetitions of the same trap ID and reports + this count here. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -37- + + +RFC-869 December 1983 + + + +B.2 Message Type 2: TAC Status + +Description + + The status message gives a quick summary of the state of the + TAC. Status of the most important features of the TAC are + reported as well as the current configuration of the + machine. + + + A TAC status message has the following form: + + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + ---------------+---------------+ + 0 | Version Number | + +---------------+---------------+ + | Last Trap Message | + +---------------+---------------+ + | Bit Flags | + +---------------+---------------+ + | Free PDB count | + +---------------+---------------+ + | Free MBLK count | + +---------------+---------------+ + 5 | # of TCP connections | + +---------------+---------------+ + | # of NCP connections | + +---------------+---------------+ + | INA A Register | + +---------------+---------------+ + | INA X Register | + +---------------+---------------+ + | INA B Register | + +---------------+---------------+ + l0 | restart/reload | + +---------------+---------------+ + | | + + Crash + + | | + + Data + + 13 | | + +---------------+---------------+ + + + + + + + + -38- + + +RFC-869 December 1983 + + + +HMP FIELDS + +System Type + + TAC = 3 + +Message Type + + TAC Status Message = 2 + +Port Number + + Unused + +Control Flag + + Unused + +Sequence Number + + A 16 bit number incremented each time a status message is + sent. + +Returned Sequence Number + + Contains the sequence number from the polling message + requesting this report. + +TAC STATUS FIELDS + +Version Number + + The TAC's software version number. + +Last Trap Message + + Contains the sequence number of the last trap message sent + to the HM. This will allow the HM to detect how many trap + messages are being lost. + + + + + + + + + + + + + -39- + + +RFC-869 December 1983 + + + +Bit Flags + + There are sixteen bit flags available for reporting the + state of various switches (hardware and software) in the + TAC. The bits are numbered as follows for purposes of the + discussion below. + + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | | | | | | | | | | | | | | | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + The bit flags report the status of the following: + + Bit Meaning + 15 0 => DDT override off; 1 => override on. + 11-14 0 => Sense Switch n is off; 1 => SSn on. + 10 0 => Traps to remote monitor; + 1 => Traps to console. + 9 1 => Message generator on. + 0-8 unused + +Free PDB count + + The number of PDBs on the free queue. + +Free MBLK count + + The number of MBLKs on the free queue. + +# of TCP connections +# of NCP connections + + The number of open connections for each protocol. + +INA Report + + These three fields report the values retained by an INA 1011 + instruction in a C/30. This instruction returns micro- + machine status and errors. In a #316, the fields are + meaningless. + + + + + + + + + -40- + + +RFC-869 December 1983 + + + +Restart/Reload + + This word reports a restart or reload of the TAC + + Value Meaning + 1 restarted + 2 reloaded + + +Crash Data + + Crash data reports the circumstances surrounding an + unexpected crash. The first word reports the location of + the crash and the following two are the contents of the + accumulator and index registers. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -41- + + +RFC-869 December 1983 + + + +B.3 Message Type 3: TAC Throughput + +Description + + The TAC throughput message reports statistics for the + various modules of the TAC. The TAC will collect these data + at regular intervals and save them awaiting a poll from the + HM. If a period is missed by the HM, the new results simply + overwrite the old. Two time stamps bracket the collection + interval (data-time and prev-time) and are an indicator of + missed reports. In addition, mess-time indicates the time + at which the message was sent. + + + A TAC throughput message has the following form: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +---------------+---------------+ + 0 | Mess-Time | + +---------------+---------------+ + | Data-Time | + +---------------+---------------+ + | Prev-Time | + +---------------+---------------+ + | Version Number | + +---------------+---------------+ + | Last Trap Message | + +---------------+---------------+ + 5 | Bit Flags | + +---------------+---------------+ + | Free PDB count | + +---------------+---------------+ + | Free MBLK count | + +---------------+---------------+ + | # of TCP connections | + +---------------+---------------+ + | # of NCP connections | + +---------------+---------------+ ---- + 10 | Host Input Throughput | ^ + +---------------+---------------+ | + | Host Input Abort Count | | + +---------------+---------------+ | + | Host Input Garbled Count | | + +---------------+---------------+ | + | Host Output Throughput | 1822 info. + +---------------+---------------+ | + (continued) + + + + -42- + + +RFC-869 December 1983 + + + + + TAC throughput (cont.) + + +---------------+---------------+ | + | Host Output Abort Count | 1822 info. + +---------------+---------------+ | + 15 | Host Down Count | v + +---------------+---------------+ ---- + | # of datagrams sent | ^ + +---------------+---------------+ | + | # of datagrams received | | + +---------------+---------------+ IP info. + | # of datagrams discarded | | + +---------------+---------------+ | + | # of fragments received | v + +---------------+---------------+ | + 20 | # of fragments discarded | v + +---------------+---------------+ ---- + | # of segments sent | ^ + +---------------+---------------+ | + | # of segments received | | + +---------------+---------------+ | + | # of segments discarded | | + +---------------+---------------+ TCP info. + | # of octets sent | | + +---------------+---------------+ | + 25 | # of octets received | | + +---------------+---------------+ | + | # of retransmissions | v + +---------------+---------------+ ---- + + +HMP FIELDS + +System Type + + TAC = 3 + +Message Type + + TAC Throughput Message = 3 + +Port Number + + Unused + +Control Flag + + Unused + + + -43- + + +RFC-869 December 1983 + + + +Sequence Number + + A 16 bit number incremented at each collection interval + (i.e. when a new throughput message is assembled). The HM + will be able to detect lost or duplicate messages by + checking the sequence numbers. + +Returned Sequence Number + + Contains the sequence number from the polling message + requesting this report. + +TAC THROUGHPUT FIELDS + +Mess-time + + The time (in 640ms. units) at which the message was sent to + the HM. + +Data-Time + + Data-time is the time (in 640ms. units) when this set of + data was collected. (See Description.) + +Prev-Time + + Prev-time is the time (in 640 ms. units) of the previous + collection of data (and therefore, is the time when the data + in this message began accumulating.) + +Version Number + + The TAC's software version number. + +Last Trap Message + + Contains the sequence number of the last trap message sent + to the HM. This will allow the HM to detect how many trap + messages are being lost. + +Bit Flags + + There are sixteen bit flags available for reporting the + state of various switches (hardware and software) in the + TAC. The bits are numbered as follows for purposes of the + discussion below. + + + + + + -44- + + +RFC-869 December 1983 + + + + + + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | | | | | | | | | | | | | | | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + + The bit flags report the status of the following: + + Bit Meaning + 15 0 => DDT override off; 1 => override on. + 11-14 0 => Sense Switch n is off; 1 => SSn on. + 10 0 => Traps to remote monitor; + 1 => Traps to console. + 9 1 => Message generator on. + 0-8 unused + + + +Free PDB count + + The number of PDBs on the free queue. + +Free MBLK count + + The number of MBLKs on the free queue. + +# of TCP connections +# of NCP connections + + The number of open connections for each protocol. + +1822 info. + + These six fields report statistics which concern the + operation of the 1822 protocol module, i.e. the interface + between the TAC and its IMP. + +IP info. + + These five fields report statistics which concern Internet + Protocol in the TAC. + +TCP info. + + + + -45- + + +RFC-869 December 1983 + + + + These six fields report statistics which concern TCP + protocol in the TAC. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -46- + + +RFC-869 December 1983 + + + +C Appendix C - Gateway Monitoring + +C.1 Gateway Parameters + + The gateway supports parameters to set Throughput and Host + traffic matrix measurements. The type of parameters and the + parameter and data pairs are as follows: + + Throughput - Type = 3 + + + Parm. Description Control Data Word + ----- ----------- ----------------- + + 1 Start/Stop 0=Stop,1=Start + 2 Collection Interval Time in 1 minute + ticks + + + Host Traffic Matrix - Type = 4 + + + Parm. Description Control Data Word + ----- ----------- ----------------- + + 1 Start/Stop 0=Stop,1=Start + 2 Collection Interval Time in 1 minute + ticks + 3 HTM Switch Control Include Control + Protocols + + + + + + + + + + + + + + + + + + + + + + -47- + + +RFC-869 December 1983 + + + +C.2 Message Type 1: Gateway Trap + +Description + + When traps occur in the gateway they are buffered. At a + fixed time interval (currently 10 seconds) the gateway will + send any traps that are in the buffer to the monitoring + center. The traps are sent as unsolicited messages. + + A Gateway trap message has the following format: + + 0 0 0 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Gateway Version # | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Size of Trap Entry | ;First Trap + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Time of Trap | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Trap ID | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Process ID | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | R0 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | R1 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | R2 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | R3 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + (continued) + + + + + + + + + + + + + + + + + -48- + + +RFC-869 December 1983 + + + +Gateway Trap Message (cont'd.) + + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | R4 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | R5 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | R6 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of this Trap | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Additional Trap reports | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +HMP FIELDS + +System Type + + Gateway = 4 + +Message Type + + Gateway Trap Message = 1 + +Port Number + + Unused + +Control Flag + + Unused + +Password or Returned Sequence Number + + Unused + +Sequence Number + + A 16 bit number incremented each time a trap message is sent + so that the monitoring center can order the received trap + messages and detect missed messages. + + + + -49- + + +RFC-869 December 1983 + + + +GATEWAY TRAP FIELDS + +Gateway Version # + + The software version number of the gateway sending the trap. + +Trap Reports + + The remainder of the trap message consists of the trap + reports. Each consists of the following fields: + + Size of Trap Entry + + The size in 16-bit words of the trap entry, not + including the size field. + + Time of Trap + + The time in (in 1/60 sec. ticks) at which the trap + occurred. + + Trap ID + + The number of the trap which is used to identify the + trap. + + Process ID + + The identifier of the process that executed the trap. + + R0-R6 + + The registers of the machine at the occurrence of the + trap. + + Count of this Trap + + The number of times that this trap occurred. + + + + + + + + + + + + + + -50- + + +RFC-869 December 1983 + + + +C.3 Message Type 2: Gateway Status + +Description + + The gateway status message gives a summary of the status of + the gateway. It reports information such as version number + of the gateway, buffer memory usage, interface status and + neighbor gateway status. + + A Gateway Status message has the following format: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -51- + + +RFC-869 December 1983 + + + + + 0 1 1 2 3 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Version Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Patch Version Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Time Since Gateway Restart | ;in minutes + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Measurement Flags | ; Bit flags to indicate which + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; measurements are on, 1= On + | Routing Sequence No. | ; Sequence # of last routing + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; update sent + | Access Table Version # | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Load Sharing Table Ver. # | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Memory in Use | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Memory Idle | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Memory Free | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # of Blks | ; Memory Allocation Info + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Size of 1st Block (in bytes) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # Allocated | + +-+-+-+-+-+-+-+-+ + | # Idle | + +-+-+-+-+-+-+-+-+ + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Size of n'th Block (in bytes) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # Allocated | + +-+-+-+-+-+-+-+-+ + | # Idle | + +-+-+-+-+-+-+-+-+ + (continued) + + + + + + + + + + + -52- + + +RFC-869 December 1983 + + + +Gateway Status Message (cont'd.) + + +-+-+-+-+-+-+-+-+ + | # of Ints. | + +-+-+-+-+-+-+-+-+ + | Int 1 Flags | ;Interface 1 Status Flags + +-+-+-+-+-+-+-+-+ ; Bit 0 - 1=Up, 0=Down + ; 1 - 1=Looped, 0=Not + +-+-+-+-+-+-+-+-+ + | Buffers | ; # of buffers on write Queue + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Time since last Status Change | ;Time since last up/dwn change + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # of Buffers Allocated | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Data Size for Interface | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Interface 1 Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + +---------------+ + | Int n Flags | ;Interface n Status Flags + +-+-+-+-+-+-+-+-+ + | Buffers | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Time since last Status Change | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # of Buffers Allocated | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Data Size for Interface | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Interface n Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # Neighbors | + +-+-+-+-+-+-+-+-+ + | UP/DN Flags | ;Bit flags for Up or Down + +-+-+-+-+-+-+-+-+ ; 0 = Dwn, 1 = Up + . ; MSB is neighbor 1 + . ; (as many bytes as necessary) + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Neighbor 1 Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Neighbor n Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + + -53- + + +RFC-869 December 1983 + + + +HMP FIELDS + +System Type + + Gateway = 4 + +Message Type + + Gateway Status Message = 2 + +Port Number + + Unused + +Control Flag + + Unused + +Password or Returned Sequence Number + + Unused + +Sequence Number + + A 16 bit number incremented each time a trap message is sent + so that the monitoring center can order the received trap + messages and detect missed messages. + +GATEWAY STATUS FIELDS + +Version Number + + The version number of the gateway sending the Status + message. + +Patch Version Number + + The patch version number of the gateway. + +Time Since Gateway Restart + + The time in minutes since the gateway was last restarted or + reloaded. + + + + + + + + + -54- + + +RFC-869 December 1983 + + + +Measurement Flags + + Flags that, if set, indicate which measurements are turned + on. Current values are: + + + Bit 0 = Message Generator + 1 = Throughput + 2 = Host Traffic Matrix + 3 = Access Control 1 + 4 = Access Control 2 + 5 = Load Sharing + 6 = EGP in Gateway + + +Routing Sequence Number + + The sequence number of the last routing update sent by this + gateway. + +Access Control Table Version # + + The version number of the access control table. + +Load Sharing Table Version # + + The version number of the load sharing table. + +Memory In Use + + The number of bytes of buffer memory that are currently in + use. + +Memory Idle + + The number of bytes of buffer memory that have been + allocated but are currently idle. + +Memory Free + + The number of bytes of buffer memory that has not been + allocated. + +MEMORY ALLOCATION INFORMATION + + The next part of the status message contains information on + the buffer pools in the gateway. The fields are: + + # of Blocks + + + -55- + + +RFC-869 December 1983 + + + + The number of different buffer pools. + + Size of Block + + The size of this block in bytes. + + # Allocated + + The number of blocks of this size that have been + allocated. + + # Idle + + The number of blocks of this size that are idle. + +GATEWAY INTERFACE FIELDS + + The next part of the status message are fields that provide + information about the gateway's interfaces. The fields are: + + # of Interfaces + + The number of network interfaces that the gateway has. + + Interface Flags + + Flags that indicate the status of this interface. The + current values are: + + Bit 0 - 1=Up/0=Down + 1 - 1=Looped/0=Not Looped + + + Buffers + + The numbers on this interfaces write queue. + + Time Since Last Status Change + + The time in minutes since this interface changed status + (Up/Down). + + # of Buffers Allocated + + The number of buffers allocated for this interface. + + Data Size for Interface + + The buffer size required for this interface. + + + -56- + + +RFC-869 December 1983 + + + + Interface Address + + The Internet address of this interface. + +NEIGHBOR GATEWAY FIELDS + + The final part of the status message consists of information + about this gateway's neighbor gateways. The fields are: + + # of Neighbors + + The number of gateways that are neighbor gateways to + this gateway. + + UP/DN Flags + + Bit flags to indicate if the neighbor is up or down. + + Neighbor Address + + The Internet address of the neighbor gateway. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -57- + + +RFC-869 December 1983 + + + +C.4 Message Type 3: Gateway Throughput + +Description + + The gateway collects throughput statistics for the gateway, + its interfaces, and its neighbor gateways. It collects them + for regular intervals and will save them for collection via + a Poll message from the Monitoring host. If they are not + collected by the end of the next interval, they will be lost + because another copy will be put into the saved area. + + A Gateway Throughput message has the following format: + + 0 1 1 2 3 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Gateway Version Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Collection Time in Min | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Number of Interfaces | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Number of Neighbors | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Number of Host Unreachable | ; # of packets dropped because + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; Host was Unreachable + | Number of Net Unreachable | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; Net was Unreachable + + ; Interface Counters + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Interface Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Packets Dropped on Input | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of IP Errors | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Datagrams for Us | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Datagrams to be Forwarded | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Datagrams Looped | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + (continued) + + + + + + + -58- + + +RFC-869 December 1983 + + + +Gateway Throughput Message (cont'd.) + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Bytes Input | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Datagrams From Us | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count that were Forwarded | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Local Net Dropped | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Queue full Dropped | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Bytes Output | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Counters For Additional Interfaces | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + ; Neighbor counters + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Neighbor Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Routing Updates TO | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + |Count of Routing Updates FROM | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + (continued) + + + + + + + + + + + + + + + + + + -59- + + +RFC-869 December 1983 + + + +Gateway Throughput Message (cont'd.) + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Pkts from US sent to/via Neig | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Pkts forwarded to/via Neighb | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Datagrams Local Net Dropped | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Datagrams Queue full Dropped | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Count of Bytes send to Neighbor | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Counters for Additional Neighbor Gateways | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + +HMP FIELDS + +System Type + + Gateway = 4 + +Message Type + + Gateway Throughput Message = 3 + +Port Number + + Unused + +Control Flag + + Unused + +Password or Returned Sequence Number + + Unused + +Sequence Number + + A 16 bit number incremented each time a trap message is sent + so that the HM can order the received trap messages and + + + -60- + + +RFC-869 December 1983 + + + + detect missed messages. + +GATEWAY THROUGHPUT FIELDS + +Gateway Version Number + + The software version number of the gateway sending the trap. + +Collection Time in Min. + + The time period in minutes in which the throughput data is + to be collected. + +Number of Interfaces + + The number of interfaces this gateway has. + +Number of Neighbors + + The number of neighbor gateways this gateway has. + +Number of Host Unreachable + + The number of packets dropped because the Host was + unreachable. + +Number of Net Unreachable + + The number of packets dropped because the Network was + unreachable. + +INTERFACE COUNTERS + + The next part of the Throughput message contains counters + for the gateways interfaces. Each interface has the + following fields: + + Interface Address + + The Internet address of this interface. + + Packets Dropped on Input + + The number of packets on input to this interface + because there were not enough buffers. + + Count of IP Errors + + The number of packets received with bad IP headers. + + + -61- + + +RFC-869 December 1983 + + + + Count of Datagrams for Us + + The number of datagrams received addressed to this + gateway. + + Datagrams to be Forwarded + + The number of datagrams were not for this gateway and + should be sent out another interface. + + Count of Datagrams Looped + + The number of datagrams that were received on and sent + out of this interface. + + Count of Bytes Input + + The number of bytes received on this interface. + + Count of Datagrams From Us + + The number of datagrams that originated at this + gateway. + + Count that were Forwarded + + The number of datagrams that were forwarded to another + gateway. + + Count of Local Net Dropped + + The number of packets that were dropped because of + local network flow control restrictions. + + Count of Queue full Dropped + + The number of packets that were dropped because the + output queue was full. + + Count of Bytes Output + + The number of bytes sent out on this interface. + + + + + + + + + + -62- + + +RFC-869 December 1983 + + + +NEIGHBOR COUNTERS + + The last part of the Throughput message are counts for each + neighbor gateway. The fields are: + + Neighbor Address + + The Internet address of this neighbor gateway. + + Count of Routing Updates TO + + The number of routing updates sent to this neighbor + gateway. + + Count of Routing Updates FROM + + The number of routing updates received from this + neighbor gateway. + + Pkts from US sent to/via Neig + + The number of packets from this gateway sent to or via + this neighbor gateway. + + Pkts forwarded to/via Neighb + + The number of packets forwarded to or via this neighbor + gateway. + + Datagrams Local Net Dropped + + The number of datagrams dropped to this neighbor + gateway because of local network flow control + restrictions. + + Datagrams Queue full Dropped + + The number of datagrams dropped to this neighbor + because the output queue was full. + + Count of Bytes send to Neighbor + + The number of bytes sent to this neighbor gateway. + + + + + + + + + -63- + + +RFC-869 December 1983 + + + +C.5 Message Type 4: Gateway Host Traffic Matrix + +Description + + The Host Traffic Matrix (HTM) message contains information + about the traffic that flows through the gateway. Each + entry consists of the number of datagrams sent and received + for a particular source/destination pair. + + A Gateway HTM message has the following format: + + 0 1 1 2 3 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Gateway Version Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Overflow counter | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Collection Time in Min | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Number of HTM entries | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | IP Source Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | IP Destination Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | IP Protocol | (unused) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Counter for SRC -> DST datagrams | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Counter for DST -> SRC datagrams | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Additional HTM Reports | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + + + + + + + + -64- + + +RFC-869 December 1983 + + + +HMP FIELDS + +System Type + + Gateway = 4 + +Message Type + + Gateway HTM Message = 4 + +Port Number + + Unused + +Control Flag + + Unused + +Password or Returned Sequence Number + + Unused + +Sequence Number + + A 16 bit number incremented each time a trap message is sent + so that the HM can order the received trap messages and + detect missed messages. + +GATEWAY HTM FIELDS + +Gateway Version Number + + The software version number of this gateway. + +Overflow counter + + The number of HTM entries lost because the HTM buffer was + full. + +Collection Time in Min + + The time period in minutes in which the HTM data is being + collected. + +Number of HTM entries + + The number of HTM reports included in this message. + + + + + -65- + + +RFC-869 December 1983 + + + +HTM ENTRIES + + The remainder of the HTM message consists of the actual HTM + entries. Each entry consists of the following fields: + + IP Source Address + + The source Internet address of the datagrams being + counted. + + IP Destination Address + + The destination Internet address of the datagrams being + counted. + + IP Protocol + + The protocol number of the datagrams. + + Counter for SRC -> DST datagrams + + The number of datagrams sent in the Source to + Destination address direction. + + Counter for DST -> SRC datagrams + + The number of datagrams sent in the Destination to + Source address direction. + + + + + + + + + + + + + + + + + + + + + + + + -66- + + +RFC-869 December 1983 + + + +C.6 Message Type 6: Gateway Routing + +Description + + The Routing message contains information about routes the + gateway has to the networks that make up the Internet. It + includes information about its interfaces and its neighbor + gateways. + + A Gateway Routing message has the following format: + + 0 1 1 2 3 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Version Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # of Ints. | + +-+-+-+-+-+-+-+-+ + | UP/DN Flags | ;Bit flags for Up or Down + +-+-+-+-+-+-+-+-+ ; 0 = Dwn, 1 = Up + . ; MSB is interface 1 + . ; (as many bytes as necessary) + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Interface 1 Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Interface n Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | # Neighbors | + +-+-+-+-+-+-+-+-+ + | UP/DN Flags | ;Bit flags for Up or Down + +-+-+-+-+-+-+-+-+ ; 0 = Dwn, 1 = Up + . ; MSB is neighbor 1 + . ; (as many bytes as necessary) + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Neighbor 1 Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Neighbor n Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + (continued) + + + + + -67- + + +RFC-869 December 1983 + + + +Gateway Routing Message (cont'd.) + + +-+-+-+-+-+-+-+-+ + | # of Networks | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Network 1 # | | | ; 1, 2, or 3 bytes + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Distance | + +-+-+-+-+-+-+-+-+ + | Neighbor # | + +-+-+-+-+-+-+-+-+ + . + . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Network n # | | | ; 1, 2, or 3 bytes + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Distance | + +-+-+-+-+-+-+-+-+ + | Neighbor # | + +-+-+-+-+-+-+-+-+ + +HMP FIELDS + +System Type + + Gateway = 4 + +Message Type + + Gateway Trap Message = 6 + +Port Number + + Unused + +Control Flag + + Unused + +Password or Returned Sequence Number + + Unused + +Sequence Number + + A 16 bit number incremented each time a trap message is sent + so that the HM can order the received trap messages and + detect missed messages. + + + + -68- + + +RFC-869 December 1983 + + + +GATEWAY ROUTING FIELDS + +Gateway Version # + + The software version number of the gateway sending the trap. + +INTERFACE FIELDS + + The first part of the routing message contains information + about the gateway's interfaces. There is data for each + interface. The fields are: + + # of Interfaces + + The number of interfaces that this gateway has. + + UP/DN Flags + + Bit flags to indicate if the Interface is up or down. + + Interface Address + + The Internet address of the Interface. + +NEIGHBOR FIELDS + + The next part of the routing message contains information + about this gateway's neighbor gateways. The fields are: + + # of Neighbors + + The number of gateways that are neighbor gateways to + this gateway. + + UP/DN Flags + + Bit flags to indicate if the neighbor is up or down. + + Neighbor Address + + The Internet address of the neighbor gateway. + +NETWORK ROUTING FIELDS + + The last part of the routing message contains information + about this gateway's routes to other networks. This + includes the distance to each network and which neighbor + gateway is the route to the network. The fields are: + + + + -69- + + +RFC-869 December 1983 + + + + # of Networks + + The number of networks that are reachable from this + gateway. + + Network # + + The network number of this network. This is the + network part of the Internet address and may be one, + two, or three bytes in length depending on whether it + is a Class A, B, or C address. + + Distance + + The distance in hops to this network. Zero hops means + that the network is directly connected to this gateway. + A negative number means that the network is currently + unreachable. + + Neighbor # + + The neighbor gateway that is the next hop to reach this + network. This is an index into the previous + information on this gateway's neighbor gateways. This + field is only valid if the Distance is greater than + zero. + + + + + + + + + + + + + + + + + + + + + + + + + + -70- +
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