The hello and holddown timers are more related to the actual adjacency. The router sends out a hello every 5 seconds to bring up adjacency's. If an adjacency is up, and it does not hear a hello for the hold time the adjacency goes down.
Now once you have an adjacency actually up, information is exchanged over that session. The integrity of that session is monitored via a different mechanism. That is where you get into the keepalive timer. Each router keeps a keepalive timer for each session. The keepalive timer has to do with actual LDP PDUs...if a router does not receive an LDP PDU after keepalive time you have a problem In summary -- LDP adjacency is your hello/hold. LDP PDU and session itself is your keepalive timer. HTH On Sat, Mar 20, 2010 at 11:50 PM, Taqdir Singh <[email protected]> wrote: > Hi all, > > LDP hello is 5 sec and keepalive is 60 sec by default... why two > timers are needed ? how two interact with each other ? > > i read that if if ldp nei.. doesnt get keepalive for 180 sec then LDP > neighborship is torn down.. but what about hello of 5 and holdown timer > (15sec) then ? > > -- > Taqdir Singh > +91 -9911709496 > +91 -8010415988 > > "do today what others wont so you can live tomorrow as others cant" > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > -- Regards, Joe Astorino - CCIE #24347 (Earned not bought) Sr. Technical Instructor - IPexpert Mailto: [email protected] Telephone: +1.810.326.1444 Live Assistance, Please visit: www.ipexpert.com/chat eFax: +1.810.454.0130 IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, Audio Tools, Online Hardware Rental and Classroom Training for the Cisco CCIE (R&S, Voice, Security & Service Provider) certification(s) with training locations throughout the United States, Europe, South Asia and Australia. Be sure to visit our online communities at www.ipexpert.com/communities and our public website at www.ipexpert.com _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
