Outbound SMTP

[Packet7]

Hello,
How does the NS decide which public IP to use on an outbound SMTP message? We have Policy based NAT configured, and instead of the traffic grabbing the external int, it grabs an IP from an inbound MIP to the same internal mail server?

Any ideas?

Thanks.

Rgds,

John Judge

 

[Njetscreamer]

When configuring an outbound policy where the system is in NAT mode the default outbound ip will be the Untrust interface IP of the netscreen. This is also true for a VIP.

However on a MIP the inbound ip (if this differs from the untrust IP) will be the MIP IP defined on the untrust interface.

E.g. say if the untrust ip was 1.2.3.4 and there was a MIP 1.2.3.5 mapping to a.b.c.d then all traffic to or from a.b.c.d will be seen to originate from the 1.2.3.5 address when traced , seen or captured on the external side of the netscreen.

hope this makes sense .

Regards

Njetscreamer

 

[Packet7]

Ah I see. So the MIP is really in two directions, not just inbound?

Thanks!

Rgds,

John Judge