[c-nsp] Verify static route next hop

[Kevin Barrass]

Hi

Cheers for the below iam testing this out now unfortunatly the routers
and IOS we are using Cisco 2851 12.4(15)T1 BASE IP does not support the
track command "track n rtr 1 reachability".
I have checked our IOS release and according to Cisco Feature Navigator
this feature should be supported. But issueing the command track 123 ?
Gives the below options:

(config)#track 123 ?
  interface    Select an interface to track
  ip           IP protocol
  list         Group objects in a list
  stub-object  Stub tracking object
  <cr>


Kind Regards

Kev

-----Original Message-----
From: Adrian Chadd [mailto:adrian at creative.net.au] 
Sent: 05 October 2007 07:13
To: Kevin Barrass
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Verify static route next hop

What you want is "Reliable Static Routing Backup Using Object Tracking"

http://www.cisco.com/en/US/products/sw/iosswrel/ps5413/products_feature_
guide09186a00801d862d.html

* setup an SLA to ICMP ECHO ping an IP
* setup a "tracking object" to track an SLA entry
* setup a default route to only trigger when that "tracking object" is
active

Works a treat. Remember that ICMP ECHO to a connected interface might
succeed if the connected interface goes down and you can reach the other
end via another path. Use source interfaces in your SLA IpIcmpEcho
entries and you should be fine.

Adrian


On Fri, Oct 05, 2007, Kevin Barrass wrote:
>  
> Hi
> 
> Iam looking into a problem where we have no option other than to use 
> static routes for political reasons ;0) Unfortunatly our core network 
> between layer 3 devices is a switched ethernet backbone.
> 
> The problem we have is that if a next hop of a static route goes down 
> the static route stays valid as the outgoing interface to the next hop

> is up.
> 
> I was told that using the command "ip route static adjust-time" there 
> is some internal feature in IOS that checks the availability of the 
> next hop IP address but in testing this does not work. Can anyone 
> advise if I have miss read the below document.
> 
> http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_featur
> e_
> guide09186a00802801fe.html