•1. In my router I have two tunnels, Tunnel1 & Tunnel2. I have created a route-map named as “SMTP” to forward the traffic of port 25 (SMTP) through the Tunnel1 & if this is not available, the traffic may go through Tunnel2. I have applied this route-map in the inbound (LAN facing toward the internal network) interface.
•2. I have created another route-map named as “PBR” which will forward rest of the traffic through ISP1 if available, else it will forward the traffic through ISP2. I have applied this route-map “PBR” as global policy (IP LOCAL POLICY ROUTE-MAP PBR).
Now, please let me know,
•a. How the route-map “SMTP” & “PBR” will action? How both of these route-maps will get the preference?
•b. How my traffic of port 25 (SMTP) will be forwarded?
•c. How the traffic other than port 25 will be forwarded?
Though you have 2 ISPs, you will have to have just 1 ISP as your default gateway at any given time.. That is, if you check your routing table, you should see only one default route and thats the path your normal traffic would take ( ei your "rest of the traffic"). As for the SMTP traffic, it will take the tunnel specified, but here the tricky part is to make sure the tunnels are tied to the proper ISP link. When the tunnels establish, they should use the correct ISP link for replying packets for the tunnel negotiation.. Because in this case, the packets leaving the router for the tunnel negotiation will be just normal traffic.
otherwise you'll run in to weird IPsec errors or when there is ISP fall back, your tunnels might not behave as expected..