port forwarding ip based

Archived from groups: alt.os.linux,alt.os.linux.redhat,comp.security.firewalls,redhat.networking.general (More info?)

Jemy wrote:
> Hi, Im new to iptables, but I wish to configure our firewall running redhat
> linux iptables to forward as follow:
> - forward traffic port 25 ip source from 123.123.123.123 to a server
> internally;
> - forward traffic port 25 ip source not from 123.123.123.123 to a server
> externally;
> is it possible to achieve the above, anyone can give a code or two
> many thanks in advance

For RH and Fedora, edit /etc/sysconfig/iptables to include something
like the following. Watch out for line wraps.

*nat
REROUTING ACCEPT [0:0]
OSTROUTING ACCEPT [0:0]
UTPUT ACCEPT [0:0]
-A PREROUTING -s 123.123.123.123 -p tcp -m tcp --dport 25 \
-j DNAT --to <"internal" ip addr>
-A PREROUTING -p tcp -m tcp --dport 25 \
-j DNAT --to <"external" ip addr>
COMMIT

Don't forget to ACCEPT the traffic in the FORWARD chain, too.

Archived from groups: alt.os.linux,alt.os.linux.redhat,comp.security.firewalls,redhat.networking.general (More info?)

On Tue, 13 Jul 2004 10:31:22 +0800, Jemy wrote:

> Hi, Im new to iptables, but I wish to configure our firewall running redhat
> linux iptables to forward as follow:
> - forward traffic port 25 ip source from 123.123.123.123 to a server
> internally;
> - forward traffic port 25 ip source not from 123.123.123.123 to a server
> externally;
> is it possible to achieve the above, anyone can give a code or two
> many thanks in advance


Nice easy firewall tool for iptables.


http://firestarter.sourceforge.net/