[1508] in linux-net channel archive
IP masquerading minor problems
daemon@ATHENA.MIT.EDU (Avery Pennarun)
Sat Dec 9 07:12:25 1995
Date: Thu, 7 Dec 1995 15:11:36 -0500 (EST)
From: Avery Pennarun <apenwarr@foxnet.net>
To: linux-net@vger.rutgers.edu
I've noticed that when IP masquerading, sometimes my connections are broken
if they remain idle for too long. I get a "connection closed by foreign
host" next time I go to type something to the telnet.
I've mostly experienced this in telnet connections from inside the
"firewall" to other computers outside the net. Both systems have been Linux
(various versions including 1.2.13, 1.3.25, 1.3.43, 1.3.45) but this doesn't
necessarily have to be the case (I haven't tried).
With masquerading disabled on the Linux gateway (running 1.3.45 right now)
and all systems with their own IP addresses, the connections keep up
perfectly despite idle time.
I imagine this is due to a missing "keepalive" response or something. I
haven't read the TCP/IP RFC's in any kind of detailed way, so hopefully
someone can help me.
Unfortunately I can't run tcpdump, since my local subnet is connected via
ARCnet, which tcpdump doesn't understand.
Have fun, all.
Avery
P.S. other than this inconvenience IP masquerading is a great idea and works
excellently!
