I have a CISCO1841 with two Fa Interfaces (Fa0/1, Fa0/1/0) connecting to two different ISPs via dialer-Interfaces.
Another Interface is connected to LAN (Fa0/0) where all the clients are.Switchports are in VLAN22 which is a DMZ with a proxy server (SQID).
All Traffic from LAN is always directed to the proxy.
Requirement is now to route all HTTP Traffic via ISP2 and all other traffic (i.e. smtp) via ISP1.
After setting up the following config, WWW seems to work properly via the right interface, also SMTP traffic
is seen on the right interface. But when attempting to upload a file (i.e. attaching a file to mail at web.de) communicationg times
out with the error-message "zero sized reply" from the proxy-server. Doing the same without the proxy-server works perfect.
Could someone look at the config and provide some hints.
Actually, you have two ways to implement your routing policy:
1- Use PBR with the route-map DSL.
In this case you don't need the set interface in NATx route-map because PBR is already forwarding the right traffic to the right interface. Your default static routes are also useless and can be removed.
2- Use the NAT rules.
In this case you need the set interface in the NATx route-map. The same route-map will allow you to match the right traffic to NAT and to forward it to the right interface. The only condition is you first need to route your traffic to any interface configured with ip nat outside command to trigger the NAT. It is already the case with your default route (it could also be a fake loopback).
We have a separation between the outside interface which is the trigger for NAT and the actual interface on which the Nated traffic is sent.
PBR is not required in this case.
So it's up to you but I prefer the first one as it looks more familiar to understand.