Hali,
saz wrote:
Hi guys, i have a problem with a configuration what i'm trying to do.
I have two computers with linux, A and B, connected in the same network with this configuration:
PC1 A: 192.168.192.1
PC2 B: 192.168.192.30
The PC1 A is a firewall doing nat... this one is connected to the internet via an adsl modem and of course it have its own public ip , and the router B is a smtp server but connected behind the router A, what i'm trying to do is redirect the smtp incoming traffic of the router A to the router B using iproute2 and nerfilter tools
This is the configuration on the router A:
*iptables -t mangle -A POSTROUTING -p tcp --dport 25 -j MARK --set-mark 1* ( this marks the smtp packets with 1 )
i create a table called "smtp" in the rt_tables file.
*ip rule add fwmark 1 table smtp* ( this is the rule for my table smtp )
and finally i declare a via in my smtp table, so the smtp traffic would have to go by this way.
*ip route add default via 192.168.192.30 table smtp*
** Ok... for example if i make a telnet to PC1 on the 25 port.. this should redirect me to PC2 where is my real smtp server, but is not working... any idea of why ? the PC2 have not a firewall..
I think you totally misunderstood a few things. Routing is a different layer (IP) than port 25 (smtp, TCP). You can not make tcp port 25 redirect using routing tools.
Here is an axample how to do it.
$IPTABLES -t nat -A PREROUTING -i $EXTERNAL_INTERFACE -s $ANYWHERE -p tcp --dport 25 -j DNAT --to-destination 192.168.1.x:25
$IPTABLES -A FORWARD -i $EXTERNAL_INTERFACE -d $INTERNAL_NET -p TCP -s $ANYWHERE --sport $UNPRIVPORTS \
-d 192.168.1.x --dport 25 -j ACCEPT
I recommend you to read a book about basic networking layers and/or iptables.
-- Udv, Nandor _______________________________________________ LARTC mailing list / LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
