Subject: [netatalk-admins] TIP ip_dynaddr patch and multi ethernet cards troubles solved.

From: "Randy Newman" <[email-masked]>
Date: Thu, 18 Feb 1999 22:57:05 -0600

This may already be common knowledge but I wasn't able to find anything on
it so here you go.

Thought I'd share my trouble and apparent fix. I was having problems with my
Netatalk Intel server using the latest non pre_asun 2.2.1 . I have two
network cards installed to route traffic between the Art Dept. Macs [using
eth1] and the rest of the office's stuff [using eth0].

My Linux server would drop the connection if I was on the 192.168.33.0
network routing through eth0_[192.168.33.15] and I was using the ip address
of eth1_[192.168.36.1].

The message in /var/log/ was ip_rewrit_addrs():shifting saddr from
192.168.36.1 to 192.168.33.15 (state 1) and the opposite would happen if I
was on the 192.168.36.0 network connecting to 192.168.33.15.

After digging I found this from IP dynamic patch's kernel source read me.
IP dynamic address hack-port v0.03-rst
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This stuff allows diald ONESHOT connections to get established by
dynamically changing packet source address (and socket's if local procs).
It is implemented for TCP diald-box connections(1) and IP_MASQuerading(2).

If enabled[*] and forwarding interface address has changed:
  1)  Socket (and packet) source address is rewritten ON RETRANSMISSIONS
it goes on .....

So I disabled the Dynamic IP patch...

  To switch off special handling of dynamic addresses (default)
     # echo 0 > /proc/sys/net/ipv4/ip_dynaddr

...and my dropped connections are solved.

Hope this will help someone else.
Ran
[email-masked]