Solved: connecting 2 ADSL connection from the same router

shibindong · ‎06-18-2008

we plan to use a router with 2 ADSL connections: 1 is dedicated for interface traffic only and the other is dedicated for VPN traffic only.

because ADSL connection gets IP and default route automatically from upstream router, there will be 2 default routes in the router,we can use policy based routing to manipulate the traffic and apply the policy on the ingress interface.

the issue is: I am not sure about the return traffic? is it return via the same path, or is it possible it will take another path back?

tomredmond · ‎06-19-2008

If the traffic leaving your router via the ADSL connection is NAT'ted to that interfaces address then the traffic will always return to the interface it left from.

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tomredmond · ‎06-19-2008

If the traffic leaving your router via the ADSL connection is NAT'ted to that interfaces address then the traffic will always return to the interface it left from.

shibindong · ‎06-19-2008

i think you are right. different interface use different NAT, the return traffic will go back via same path without any other config.

lagos · ‎06-19-2008

I would put the 2nd Dialer interface into a VRF:

interface Dialer1

ip vrf forwarding dsl2

ip address negotiated

The tunnel interface can be sourced from the Dialer:

interface Tunnel1

ip address 192.168.252.14 255.255.255.240

tunnel source Dialer1

tunnel vrf dsl2

tunnel protection ipsec profile spokeprof

This will solve the issue with return traffic, NAT limitations, etc. The tunnel interface itself exists in the global routing table.

HTH!

CJ