Ciscoworks LMS 3.1 device discovery via Routing Table and BGP

Unanswered Question
Jun 22nd, 2009

Can someone please explain the concept of device discovery via Routing Table and BGP? I have 300+ remote networks, typically a router and a switch connected to the HQ via provider MPLS VPN. BGP is the protocol used. From the HQ WAN router perspective, it will not see any of these network devices as CDP neighbors. The WAN router do see all the remote networks in BGP and Route table. I am looking for a solution without having to manually add 750+ network devices.

I've added 1 of the networks in the Seed Device Settings and that network was discovered via CDP without any problem. I am also trying to avoid this approach, cuz I would have to add 300+ devices in my Seed Device Settings.

Thanks in advance.

I have this problem too.
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Joe Clarke Mon, 06/22/2009 - 14:49

When you use the BGP module, Discovery will poll the bgpPeerRemoteAddr object to find peer IP addresses from seed devices. It will then poll those peers with SNMP to get their peers and so on.

With the routing table discovery, the entire table is fetched via SNMP, and each of the next hops IPs are polled using SNMP.

Martin Ermel Mon, 06/22/2009 - 23:58

if the branches are terminating on a few routers in the HQ, perhaps this solution should be practible for you (just an idea)

setup 2 discovery jobs:

a) with BGP as the discovery module and a hop count of 1, add the HQ routers as seeds or add these seeds from a file, Do not use DCR as seed;

this should fill-up DCR with one device of each branch and should find automatically a new branch if it will be connected to one of the seeds

b) with CDP as the discovery module, no hop count and 'Use DCR as seed'

this will fill-up DCR with the devices of the HQ and all branches

schedule b) to run around 30 min after a) has finished

situwayne Tue, 06/23/2009 - 09:08

unfortunately the branches are not directly connected to the HQ WAN routers. they are directly connected to provider router. HQ WAN router is also directly connected to provider edge router. the communication between HQ and branch is via provider MPLS.

Joe's explaination on BGP makes sense. the reason I can't discover the branches is cuz my WAN router cannot get through it's directly connected neighbor (which is owned by ISP).

as much as I hate to enter all subnets individually in the Seed file, it is my only solution now.


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