2.4.0 tcp over firewall - no connection

[Eugene Crosser]

I noticed rather strange behavior: stock 2.4.0 with old ISA 3Com
on UP compiled as UP cannot open TCP connection to hosts behind a
firewall.  E.g. it is impossible to go to http://www.etrade.com/ -
connect just never finishes.  2.2.17 on the same hardware works
right.  2.4.0 on SMP over PPP connection works right too.  MTU
is 1500 in both cases.  In both cases, kernel is compiled with
netfilter as modules, but those are not loaded.

I did not investigate further yet, just wanted to bring this to
attention of those whom it may concern...

Eugene