iptables and dump/rmt

[Benjamin Stocker]

Hy all,

i'v found a problem using iptables and dump/rmt which I cannot solve, I
even found nothing in the NG's and in the netfilter mailing list.

I use a iptables FW with kernel  2.4.10 and iptables  v1.2.2

I have a webserver behind the firewall and a backup server outside the
firewall. The webserver is backing up its local data through the
firewall to the backup server using dump and rmt.

Here is what I've done:

I have another webserver not behind the firewall. This server has no
problems to do backups.

When I connect from the webserver behind the fw to the backup server
using rsh or rlogin, everything works well. AFAIK, dump/rmt also uses
the rtools to do remote backup. The FW does routing and SNAT pretty
well.

But when i use dump using the same account, I get this error message
from dump:

  DUMP: poll: protocol failure in circuit setup
  DUMP: login to merkur.vsonline.ch as backup failed.

and /var/log/messages on the backup server reports:

  XINETD[pid] START: shell pid=<pid> from=<firewall's ip>
  rshd[pid]: connect second port: Connection refused

The firewall log shows nothing.

Thanks for help.
Benjamin