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(ldp): active/passive

maher
Level 1
Level 1

Hi,

Just want to know, normally, I get xmit/recv, but from this output, it shows active/passive. What could it be if the active/passive status is shown in below command?

PE1#sh mpls ldp discovery

Local LDP Identifier:

192.168.1.97:0

Discovery Sources:

Interfaces:

FastEthernet0/1 (ldp): xmit/recv

LDP Id: 10.1.1.43:0

Targeted Hellos:

192.168.1.97 -> 192.168.1.98 (ldp): active/passive, xmit/recv

LDP Id: 192.168.1.98:0

Thanks in adavance.

maher

4 Replies 4

pkhatri
Level 11
Level 11

Hi Maher,

I'm not sure if this what you are asking but 'active' indicates that this LSR has initiated targeted Hello messages.

The passive field indicates that the neighbor LSR has initiated targeted Hello messages and that this LSR is configured to respond to the targeted Hello messages from the neighbor.

Hope that helps,

Paresh

mheusinger
Level 10
Level 10

Hello Maher,

targeted LDP has two "components".

First you see active/passive. This means according to the configuration of the LSR it should send LDP unicast hellos to the specified IP address (active). It also is configured to accept and respond to LDP unicast hellos from the specified IP address (passive).

Second you see xmit/recv. This tells you, what the LSR does at the moment. Only "xmit" tells, that the LSR is sending hellos, but not receiving any. Only "recv" tells you, that there are hellos from the specified IP received, but no hellos sent (usually because the IP is not found in the routing table). The display of "xmit/recv" tells that hellos are sent and received, which is the prerequisit for a LDP TCP session.

Hope this helps! Please rate all posts.

Regards, Martin

AFAIK, the concept of active/passive in LDP has nothing to do with whether the hellos are targetted or using the multicast addresses. In both cases LDP has to chose one of the LSRs to be the active one, hence initiate the session, and the passive LSR waits for the active LSR to initiate the session. The active LSR is the LSR with the highest IP address for its transport connection.

Dear all,

Thanks for the above info. Really appreciated.

cheers,

maher