Slight correction, if I may: it's not that OSPF will declare a link dead after it fails to receive four packets. It will declare the link dead after it has not received any hello packets for the duration of the configured dead timer. By default the dead timer on a broadcast medium is equal to four times the hello interval, so this would indeed work out to four packets. But you could set the dead timer to 11 seconds if you really wanted to, and OSPF would declare the link dead after 11 seconds had passed without hearing a hello packet. BJ ss wrote: Hi!! OSPF uses hello packets as keepalive message.This is exchanged periodically at regular intervals between the neighbors to check if the link is alive.Suppose if the link goes down then the neighbor will not receive hello packets which means there is some problem in the link.If the neighbor does not receive 4 consecutive hello packets at the intervals defined ,then the neighbor is considere dead. After sometime if the neighbor again comes up,the router has to again establish the neighbor relationship. Hope this helps you Cheers ss Bradley J. Wilson CCNP CCDP MCSE NNCSS CNX MCT CTT EDS/Boston Scientific Account (508) 650-8739 [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=15008&t=15008 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
