Raj, This one comes straight from RFC 2328. The IP destination address for the packet is selected as follows. On physical point-to-point networks, the IP destination is always set to the address AllSPFRouters. On all other network types (including virtual links), the majority of OSPF packets are sent as unicasts, i.e., sent directly to the other end of the adjacency. In this case, the IP destination is just the Neighbor IP address associated with the other end of the adjacency (see Section 10). The only packets not sent as unicasts are on broadcast networks; on these networks Hello packets are sent to the multicast destination AllSPFRouters, the Designated Router and its Backup send both Link State Update.
HTH, Elmer ----- Original Message ----- From: "Rajesh Kumar" To: Sent: Thursday, February 14, 2002 9:38 AM Subject: Hello packets mcast or ucast in Multipoint networks? [7:35395] > Hi all, > > Here is the question that I have. > > In Routing TCP/IP vol 1 by Jeff Doyle - OSPF chapter pg 417 under P- > MP paragraph - it says OSPF packets are mcast. > > On Pg 433, 1st paragraph, 4th line it says Hellos are ucast in Point to > Multipoint networks. > > > Can somebody share with their explanation? > > Thanks > rajesh Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=35461&t=35461 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
