MTU problem with 2.0.26?

Ronan Mullally (ronan@iol.ie)
Tue, 26 Nov 1996 15:49:18 +0000 (GMT)

I upgraded 3 WWW cache servers from 2.0.24 to 2.0.26 yesterday. In the
process I changed their ethernet cards from 3c590s to 3c905s running at
10Mbps (I'm using the current 3c59x driver from ftp.cesdis.nasa.gov).

We have a frame relay network which doesn't like an MTU larger than 1006
bytes, since upgrading the servers people have been having problems
connecting to them, getting as far as 'host contacted, waiting for reply',
then nothing. A packet trace shows the TCP session being opened then
hanging. I've come across this in the past and over-size packets are
the culprit.

I ifconfig'd the mtu on the ethernet interfaces to 1006 and the problem
disappeared, however the rest of our servers (2.0.24, 2.0.25 and Solaris)
all use an ethernet MTU of 1500 without any problems.

Has anything changed in the network code (fragmentation?) for 2.0.26 which
would cause this to happen, or would the 3c905 be at fault?

-- 
 Ronan Mullally                        'In the Beginning there was
 Network Manager                        nothing, which exploded.'
 Ireland On-Line                           -- Terry Pratchett.