what is difference between LDP hello packets, LDP holdtime and KA interval?

[junaide45]

    Peer LDP Ident: 10.16.16.16:0; Local LDP Ident 10.15.15.15:0

        TCP connection: 10.16.16.16.11013 - 10.15.15.15.646

        State: Oper; Msgs sent/rcvd: 53/51; Downstream; Last TIB rev sent 74

        Up time: 00:11:32; UID: 1; Peer Id 0;

        LDP discovery sources:

          Targeted Hello 10.15.15.15 -> 10.16.16.16, active, passive;

            holdtime: infinite, hello interval: 10000 ms

        Addresses bound to peer LDP Ident:

          10.0.0.2        10.16.16.16     10.101.101.101 11.0.0.1        

        Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab

[junaide45]

LDP peering went down for 6 seconds

I am willing to know; what role hello interval and KA interval play in declaring LDP peering down

and ehat holdtime is reponsible for?

[skanuri]

LDP Hold time is the time the router waits before declaring the LDP session down.

     a) Discovery hold timer

               used during session establishment.

     b) session hold timer

               used once the TCP connection is established.

Hello time interval is the period LDP hello's are generated to discover the neighbors.

Keep alive interval is the period LDP keepalives are sent once the session is established b/w the neigbhors.

Hope this helps.

[junaide45]

hello interval is 5sec. .... discovery holdtime is 15s

KA interval is 60s .... session holdtime is 180s

if a router missed 3 hello packets, he will declare its neighbour down

then KA will be sent every 60s; after missing 3 KA msgs the router will remove neighbour from his database

1. till what time router will keep on sending MPLS traffic?
2. whether after ending of discovery holdtime or after session holdtime router will divert traffic to other redundant mpls path?
3. after LDP neighborship is down, whether hello packet or KA packet will continue to be sent?

Thanks for replying