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Community Member

Serial line as backup to ADSL link


I have 2 locations, one head office and one branch office.

In the head office I have one 1700 series router with an ADSL line and one serial link that connecting to my Branch office. In the Head office we have all the applications and exchange servers are installed and the head office LAN network is

The branch office users are using internet via the ADSL line in the Head office.

The LAN network used in my branch office is

I am not using any dynamic routing protocols in this scenario. Only static routes are in present.

Now I got one ADSL line in the branch office and I configured this ADSL line as the primary internet connection for the users in branch office, and the point to point serial link is only use for the exchange and other applications.

I would like to achieve redundancy for the ADSL line in the branch office as, If the ADSL line in the branch office down, the users should able to use internet through the point to point serial link, using the ADSL line in the head office. (The serial link should also act as the backup for ADSL line)

The routes are in branch office router,

Ip route dialer 1

Ip route serial 0

(Nat is enabled on the router)

Please help me to finding a solution for this..



Community Member

Re: Serial line as backup to ADSL link


You can deploy a feature called Object tracking or reliable static routes. Since the next hop reachability is very important in a ADSL environment.

if any queries please drop me an email on

i will send u a sample config and also docs related to that.

Thanks and Regards,

Srinath . Muralidharan


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