ongoing problems with broken Path-MTU-discovery on servers at cvshome.org/OpenAvenue.com

[Greg A. Woods]

Can someone please clue in the appropriate people that there's a very
SERIOUS problem with the servers at cvshome.org and/or OpenAvenue.com.
Both the anonymous CVS server, and the anonymous FTP server are failing
to do proper Path-MTU-discovery (probably because of a broken or
mis-configured firewall or router somewhere between those machines and
above.net).  Above.net folks have assured me that they do not filter
anything, and I know they're at least partly right since I can FTP to
other above.net clients just fine.  The problem can only be at
cvshome.org/OpenAvenue.com.

This has been broken for several months now.

Until this is fixed everyone (such as myself) who resides behind a
router with a smaller-than-1500-byte MTU will continue to be unable to
either check out the CVS source with CVS, or to retrieve files from the
FTP server.

CVSHOME.ORG / OpenAvenue.com:

You must *NOT* ever filter, drop, or otherwise inhibit valid ICMP error
messages since doing so breaks the correct operation of TCP.  ICMP is a
very critical part of the TCP/IP protocol suite and it is absolutely
necessary that it function correctly for any server doing PMTUD.  At the
bare minimum PLEASE immediately disable Path-MTU-discovery on your
servers until the errant firewall/router/whatever is found and fixed!

-- 
                                                        Greg A. Woods

+1 416 218-0098      VE3TCP      <address@hidden>      <robohack!woods>
Planix, Inc. <address@hidden>; Secrets of the Weird <address@hidden>