Pass traffic from a LAN interface through specific Dialer interface

[CHARALAMPOS TRIANTAFYLLIDIS]

Hi,

A customer has a Cisco 2821 router with two ethernet interfaces and two HWIC interfaces connected to different ISPs.

Interface G0/0 has private IP address 10.10.10.10.

Interface G0/1 has a public IP address from a pool of IP addresses from ISP-A.

Dialer0 connects router to ISP-B.

Dialer1 connects router to ISP-A.

Both Dialers has static Public IP addresses.

Router has default route 0.0.0.0 0.0.0.0 Dialer1.

We want all traffic that arrives to interface G0/0 to pass through Dialer0.

What we have done is:

First we created an extended access list using the following commands:

ip access-list extended VIVODI

permit ip any any

Then we created a route map using the following commands:

route-map MAP_VIVODI permit

match ip address VIVODI

set interface Dialer0

We relate the route map with the G0/0 interface using the commands:

interface G0/0

ip policy route-map MAP_VIVODI

We create the NAT rule:

ip nat inside source route-map MAP_VIVODI interface Dialer0 overload

The result is not the expected. We tried to change the access list to test only the HTTP traffic with no success (permit tcp any any eq www).

Can someone help us?

What is wrong with the configuration?

We used the same configuration to pass HTTP traffic to a specific Dialer to another client with success but in that case we have one Gigabit interface.

Can someone suggest us what we must do?

Thanks in advanced.

[Giuseppe Larosa]

Hello Charalampos,

>> The  result is not the expected.

May you describe what is happening?

I would try with the following changes:

int g0/0

ip nat inside

no ip  policy route-map MAP_VIVODI

int dialer0

ip nat outside

the reason is that the set interface is already there in the route-map that is invoked for NAT so one use of it should be enough.

Hope to help

Giuseppe

[CHARALAMPOS TRIANTAFYLLIDIS]

Hi giuslar,

thanks for your reply.

>> The result is not the expected.

means that the router loses connection to the internet from both interfaces.

What do you mean by saying:

>> set interface is already there in the route-map that is invoked for NAT so one use of it should be enough.

The set interface Dialer0

isn’t the command that describes which Dialer should by used to forward the traffic?

The command:

ip  policy route-map MAP_VIVODI

doesn’t describe that the route map will be used by the G0/0 interface?

Thanks.