From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc1435.txt | 115 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 doc/rfc/rfc1435.txt (limited to 'doc/rfc/rfc1435.txt') diff --git a/doc/rfc/rfc1435.txt b/doc/rfc/rfc1435.txt new file mode 100644 index 0000000..414682e --- /dev/null +++ b/doc/rfc/rfc1435.txt @@ -0,0 +1,115 @@ + + + + + + +Network Working Group S. Knowles +Request for Comments: 1435 ftp Software + March 1993 + + + IESG Advice from Experience with Path MTU Discovery + +Status of this Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard. Distribution of this memo is + unlimited. + +Abstract + + In the course of reviewing the MTU Discovery protocol for possible + elevation to Draft Standard, a specific operational problem was + uncovered. The problem results from the optional suppression of ICMP + messages implemented in some routers. This memo outlines a + modification to this practice to allow the correct functioning of MTU + Discovery. + +Advice on the Deployment of Path MTU Discovery Protocol + + While reviewing the Path MTU Discovery Protocol for Draft Standard + [RFC1191], the Internet Engineering Steering Group (IESG) became + aware from the reports of various implementors that some vendors have + added to their routers the ability to disable ICMP messages generated + by the router. This is to protect older BSD hosts, which would drop + all connections to a host it found an ICMP message on any of the + connections, even if it was a non-fatal ICMP message. While this + protects older BSD hosts, it causes MTU discovery to fail in a + silent, hard to diagnose way. + + From the descriptions the IESG has obtained, adjusting the routers to + continue to send ICMP message Type 3 code 4 (destination unreachable, + don't fragment (DF) bit sent and fragmentation required) even when + they have their "don't send ICMP messages" switch turned on would + allow path MTU discovery to work but not effect older BSD hosts, + since they never set the DF bit in their packets. + +Author's Note + + This document was the result of an IESG meeting discussing MTU + Discovery. This author was chosen to write the document as the + Internet Engineering Task Force (IETF) Internet Area Director. + + + + + +Knowles [Page 1] + +RFC 1435 IESG Advice from Experience with Path MTU Discovery March 1993 + + +References + + [RFC1191] Mogul, J., and S. Deering, S., "Path MTU Discovery", + RFC 1191, DECWRL, Stanford University, November 1990. + +Security Considerations + + Security issues are not discussed in this memo. + +Author's Address + + Stev Knowles + ftp Software + 2 High Street + North Andover, Ma, 01845 + + EMail: stev@ftp.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Knowles [Page 2] + \ No newline at end of file -- cgit v1.2.3