Is there any way in IOS to use a ping to a specific IP address as a keepalive? I am trying to implement a failover between two ISP connections without using BGP. I want the connection to switch to the backup if Layer 3 reachibility is lost, not when the Layer1 or Layer2 link fails.
Incoming traffic is not important, so there is no need to announce a specific subnet. The outgoing traffic will be nat'ed to an address on the outbound gateway device, so return traffic will traverse that link.
I know that there are other products that will do this, but don't know of a way in IOS.
I do not know of a way to do this, either. However, With co-operation of your ISP, there are several possibilities.
One would be to use a GRE tunnel and floating static routes. The Tunnel uses TCP keep-alive, and would provide a L3 way to tell if the path to your ISP was functional.
Another way would be to have your ISP send you a host route in any convenient routing protocol. You could then use a route map / Default information originate based on the existence of this route. Most of the IGP routing protocols will do this.
A third way to consider would be to run ODR, and allow CDP to discover the next hop on the ISP network. I would have to try that before I was sure it would work, and the ISP would have to have Cisco routers.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.