Cisco 1841 WIC 1 ADSL Configuration

[david.santel]

I am configuring a 1841 router for use in small out office. I will use the s0/0/0 for main WAN T1 connection. I then wanted to use the ATM0/1/0 WIC-1-ADSL card as a failover.

I am using weighted static routes for failover. Fe0/0 is LAN interface.

When I go into SDM and look at the ATM interface it says this configuration is unsupported? 

1. Can't I just get a DSL modem and connect it to fe0/1 and not use ATM WIC and use below for failover?

2. If I have to use ATM WIC what needs to be configured for it to work with Att aDSL?

interface ATM0/1/0

no ip address

ip nat outside  

ip virtual-reassembly

shutdown

no atm ilmi-keepalive

dsl operating-mode auto

ip route 0.0.0.0 0.0.0.0 Serial0/0/0

ip route 0.0.0.0 0.0.0.0 ATM0/1/0 100

ip nat inside source route-map outside_nat interface Serial0/0/0 overload

ip nat inside source route-map outside_nat_failover interface ATM0/1/0

route-map outside_nat_failover permit 1

match ip address 100

!

route-map outside_nat permit 1

match ip address 100

Extended IP access list 100

    10 permit ip 192.168.16.0 0.0.0.255 any

    20 permit ip host 192.168.17.2 any

    30 permit ip 192.168.18.0 0.0.0.255 any

    40 permit ip 192.168.20.0 0.0.0.255 any

[mavespig]

Hi David,

Just one suggestion about the config.

ip route 0.0.0.0 0.0.0.0 Serial0/0/0  -> this router will remain in routing table, until the serial interface goes down.

Typically, your serial port is connected to a Telco device (CSU/DSU). This means that if there is a network failure (behind the telco device), your serial port will still be up/up, even if there is no connectivity.

You may use an IP SLA to track the reachability of a remote IP, and add the track to the route command.

Regarding the DSL link, ATM is just the lower layer, you shouldn't configure L3 there. You need to add a dialer interface over it, and use the dialer in the NAT/route commands.

Example of configuration:

http://www.cisco.com/en/US/tech/tk175/tk15/technologies_configuration_example09186a008071a60e.shtml

Hope this helps

Marco