I have an DNAT ISSUE with PREROUTING.
This is my setup.
I have 2 firewalls running iptables.
188.8.131.52/29 is the internet interace of FIRST firewall.
184.108.40.206/29 is the internet interface of SECOND firewall. it has DMZ zone. in that DMZ zone, mail server runnig @
Now I want to DNAT port 25 of FISRT firewall (
i.e - its ip address - 220.127.116.11/29) to the internet ip address (
18.104.22.168/29) of SECOND firewall. That firewal DNATs port 25 to mail server @
192.168.100.3 in DMZ zone.
These are rules I have added.
FIRST firewall (its internet ip address - 22.214.171.124/29
) I have addes below rule.
iptables -t nat -A PREROUTING -p tcp -i eth0 -d
126.96.36.199 --dport 25 -j DNAT --to-destination
That should forward port 25 to SECOND firewall. in SECOND firewall, I have added 2 below rules.
iptables -t nat -A PREROUTING -p tcp -i eth0 -d 188.8.131.52 --dport 25 -j DNAT --to-destination
iptables -A FORWARD -p tcp -d
192.168.100.3 --dport 25 -m state --state NEW -j ACCEPT
Now, it should forward port 25 to mail server @ DMZ Zone.
I think I have added these rules properly. But, It does not work.
I checked from outside world . I telneted to port 25 of first firewaal. Then, It should forward to mail server @ DMZ zone.
But, no responce.
WHY is that?
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