re "corrupted MAC on input"

[Chris <sea_dragons_(_at_)_mac_(_dot_)_com>]

For the archives:

	I wrote ages ago whether anyone had insight on ssh disconnections 
with the error message "corrupted MAC on input" and just recently was 
contacted by a fellow with totally different hardware and software on 
both OpenSSH client and server.  The sole common link in the affected 
setups:  connections that ran through a Linksys 4-port router/switch.

	Advertised as good for small offices, it is perhaps avoided by 
people who require persistent ssh connections (e.g., connects to a 
machine using ports enabled only by authpf and thus only while OpenSSH 
connections persist) at any point in the intervening network.

	Best regards,
	Chris

The conversation:

Glenn:
Hi -- I noticed your Neohapsis post about your ssh connections dropping
with a "corrupted mac on input" error.  I'm also getting a lot of dropped
connections with the same error.  Did you ever learn of a fix, or what's
causing the problem?

Chris:
# I did not find any particular fix.  It remains a puzzlement.  I am
# unsure whether networking hardware between the machines, foibles within
# one or more of the machines themselves, or cosmic rays are the culprit.
# What hardware have you seen this between?

Glenn:
Thanks for the reply.  The hardware involved are all Pentium-class
Linux boxes.  It's happening over my wireless network, which is based
on a Linksys access point.

Chris:
# Ahh ... all my affected machines were attached in one way or another to
# a 4-port Linksys router ....
#
# Verrrrry interesting.  I will experiment with boxes connected 
wirelessly
# without the intervening Linksys device.  But it will require me to get
# time to re-arrange my network.

Glenn:
Aha!  Yes, I'm using one of those 4-port switch, DSL router, wireless
access point combo-units.  My server (the machine I connect *to* a lot)
in plugged into one of the switch ports.  I'm usually connecting *from*
my laptop over wireless.