SNMP Supervision issue

[Florent CHETAIL]

Hi all,

i have an issue with a link between a Cisco 7609 and a Cisco 7606.

This link is managed by a service provider with their own routers.

I want to check regularly if the connectivity between my 2 routers is correct (i don't want to check physical status but at least layer 2 status)

I browse the mib of my equipement and found in the "cdpcache-->cdpcachetable.cdpcacheentry", many instances of neighbors :

- Instance 10.23

- Instance 11.20

- Instance 13.21

- Instance 24.17

- Etc....

Every Instance correspond to one of router's neighbors.

I decide to have a comparison of the cdpcachedeviceid, witch is the name of my router, in my instance and everything is working fine

But when i have a cut on the link, the instance disappear in the cache and when it reappears, it take another number

So my monitor didn't get up until i change it manually

I also tried to find LDP or OSPF neighbors fields but i didn't find anything.

Any Ideas ?

Many Thanks

Florent

[Marvin Rhoads · Accepted solution]

Wouldn't it be better to get syslog entries re the event that happens (such as routing adjacency change) when the intermediate link is lost? You can then define an action (email, raise alert etc.) when that specific syslog entry arrives.

You could also query the routing table and look for certain objects (routing entries) that are only present when the remote site is reachable.

[Florent CHETAIL]

Hello Marvin & Vinod,

Thanks for your response.

Vinod, i don't believe my interface goes operationnally up/down if i have a cut, the network between my 2 routers is a MPLS.

Marvin's solutions are probably the best except that i didn't find any object at the routing level

I didn't want to intercept trap or syslog but it may be this only one solution.

Thanks

[Marvin Rhoads]

Can you query the IP route table object and look for a particular route that's only present when your remote site peer is reachable?

[Florent CHETAIL]

the IP route table object is empty like many other ospf object...

thank you for the link, i didn't know about this tool !

I didn't find any object on mpls ldp neighbor (because I use MPLS on my network), do you know if something like that exist ?

[Vinod Arya]

Marvin has a valid point. As my 2 cents, you can also try to monitor the operational status of the interface via SNMP so, if the neighbour goes down it shows operationally up/down with same index to monitor.

As another option, you can configure an EEM to track the interface and if it goes down, EEM can alert you via email/syslog/trap etc.

-Thanks

Vinod