Mapping outbound traffic to external IP.

[bmvportland]

I have couple of external IP addresses x.x.x.61 and x.x.x.69. I use the x.x.x.69 for NAT. My mail server (192.168.y.20:25) sits behind the firewall and is mapped to the external address x.x.x.61:25. There is no issue with incomming mail. The problem is that when mail is sent out the message appears as comming from x.x.x.69:25 and not from x.x.x.61:25. Some providers (e.g. Comcast) reject the mail based on the fact that the reverse look up does not match.

Is there a way to setup IOS to map outgoing traffic from 192.168.y.20:25 to x.x.x.61:25?

[Jon Marshall]

Hi

In IOS

ip nat inside source static tcp 192.168.y.20 25 x.x.x.61 25 extendable.

Just out if interest is it IOS you want to do this in or on the firewall ?

If the firewall is a pix then

static (inside,outside) tcp x.x.x.61 25 192.168.y.20 25 netmask 255.255.255.255

HTH

Jon

[bmvportland]

Thanks for your quick reply.

I already have the "ip nat inside source...." command. The inbound traffic is routed just fine. It is the outbound traffic that keeps going out as x.x.x.69:25 since the x.x.x.69 is the external NAT IP. What I am looking for is to map the internal 192.168.y.20:25 to x.x.x.61:25

[Fernando_Meza]

Hi ..

If you are using a PIX, then you need to use static NAT instead of port forwarding meaning that you need to use.

static (inside,outside) public_IP Private_IP netmask 255.255.255.255

I hope it helps .. please rate if it does !!!