Hy all,
I'm using a linux firewall with two ethernet interfaces + iptables +
masquerading (for windows clients) + NAT 1:1 (for application servers).
My external interface, eth0, has 3 ip adresses (ip aliasing) destined to
make 1:1 NAT for 3 internal servers.

When some internet machine connects to one of my internal servers, let's say
server1, it will connect to the firewall's external aliased ip(eth0:0 -
200.111.111.111) which will be managed by the following rule:
$IPTABLES -t nat -A PREROUTING -d 200.111.111.111 -j DNAT --to-destination
$SERVER1_INTERNAL_IP

But, when server1 starts a connection to the outside world, it will match
the default masquerading rule to all internal machines:
$IPTABLES -t nat -A POSTROUTING -o eth0 -j SNAT --to-source 200.111.111.110

What perturbs me is: when server1 answers the outside world it will show a
source ip 200.111.111.111. But when server1 starts a connetion to the
internet, it will use the ip 200.111.111.110 - the ip of the firewall's
eth0.

Does it offer any problem? How are you dealing with this case?
Don't I need an additional rule as:
iptables -t nat -A POSTROUTING -o eth0 -j SNAT -s $SERVER1_INTERNAL_IP -j
SNAT --to-destination 200.111.111.111
??

thank you all,
-------------------------------------------------
 -- Bruno Negr�o -- Suporte
 -- Plugway Acesso Internet Ltda.
 -- (31)34812311
 -- [EMAIL PROTECTED]

_______________________________________________
Firewalls mailing list
[EMAIL PROTECTED]
http://lists.gnac.net/mailman/listinfo/firewalls

Reply via email to