Routing Outgoing SMTP traffic through a secondary broadband connection.

[geezgeez]

Hi,

At work I have two broadband connections, I will refer to them as A and B.

Broadband connection A is connected to a netgear ADSL router, which then connects to the external interface of a watchgaurd firewall. The firewall on the netgear router has been disabled as well as NAT, and the watchguard firewall handles all aspects of security.

The watchguard then connects to a switch which has 3 other switches daisy chained to proved ethernet connections to our 100 + network connections around our office building.

Now the currently through Broadband Connection A all external network traffic goes out through that, smtp, http, connections to external sites via vpn (i.e. accessing network shares in our office in london).

The bulk of outgoing network traffic appears to be smtp, from our exchange server (5.5, soon to be 2003 in the next couple of weeks), and from mobile users who are from the London site who send emails via a linux server located offsite.

Now I want to reroute this smtp traffic through Broadband Connection B, which has recently been installed. This is also connected using a Netgear ADSL modem, with a basic firewall enabled (will be attached to a another watchguard soon which will take over the firewall functionaility). The netgear router then connects directly into our series of daisy chained switches.

I have tried setting up a rule in the watchgaurd to foward all outgoing smtp traffic to the local IP of the netgear router connected to Broadband Connection B.

But so far this has not worked, when the rule is applied to forward all smtp to the local ip of the netgear router connected to Broadband Connection B, in the Exchange mail queue, emails will just sit there with the error message "Host Unreachable".

Now the router attached to Broadband Connection B appears to be working in relation to routing traffic to the local network. If I manually assign this router to be my gateway, I am still able to browse the internet and access most network shares (our main windows 2003 server).
But I am not able to open up my outlook and see my mailbox, or connect directly to the server using \\hostname but \\ipaddress does work.

Is there something I am missing?