Need some Cisco router help - backup DSL internet

flashlightlens

Newly Enlightened
Joined
Nov 12, 2002
Messages
134
Location
flashlightlens.com
I need to know this:

I have a 2612 that has no open serial or ethernet ports - all are being used.

Serial 0/0 - point to point location B
Serial 0/2 - point to point location A
Ethernet 0/0 - local LAN

There's a serial 0/1 listed, but I can't see where this would be - is this the huge slot to the left?

In any case, current internet traffic comes from location A over the P2P. I have a secondary DSL internet line coming in and would love to be able to use it for a failover for outbound internet at this location. I've read about using DSL that comes in and utilizes a WIC and "floating routes" that prioritize the two different outbound IP routes. I've basically got DSL on an ethernet line. Is there any way to use this as a failover without having an available ethernet port on the router? Also, how can I spilt the internet traffic away from the P2P. This scenario is assuming the P2P stays up and the internet fails at location A.

Does this make sense?
 

KevinL

Flashlight Enthusiast
Joined
Jun 10, 2004
Messages
5,866
Location
At World's End
Just a couple thoughts without knowing too much about the specifics of your setup..

The large slot that takes up nearly half of the router is the network module (NM) bay. Unless it has a module installed, it will have no interfaces. A picture would be useful. Serials can either be in the NM bay (4-port module) or in the WIC bays (1 or 2-port modules).

There is a native ADSL WIC into which you can plug a RJ11 phone line and have it provide modem functionality, true. There's also another low-speed (10Mbps only) Ethernet WIC that you can buy for your DSL Ethernet setup. You will need a WIC or another Ethernet port because routers work on an interface basis. Unfortunately it doesn't seem possible to put it on the same Ethernet line (can be done, but would be ridiculously complex and expensive and involve another router).

A floating static route works as such - it has a higher administrative distance (lower priority.. sorta). When the default route stops working because of Serial0/2 going down, the floating static takes over and sends the data over its route (over the secondary DSL link). Note that for the floating static to work, the router must be able to detect Serial 0/2 going down. If for example, another router at site A goes offline, your router will not be able to know assuming you don't run a routing protocol. If you do, it's a whole different kettle of fish. Hope this helps.
 
Top