> I have a question about OSPF over DDR. The lab scenario is: > > 1. RTA and RTB connect with each other using back-to-back connection with > serial PPP connection, and use the asynchronous interface as the backup > interface. > > 2. And on each router there is a ethernet interface as a stub network. All > the networks run ospf and belong to 3 areas respectively. PPP and its > backup links are all in the area 0. > > 3. I have use the "broadcast" key word in the rout map, and correctly > define the dialer-list with ip permit. > > Question: > When the primary PPP link is down, the DDR works correctly. But there is > not hello packet can be find on the DDR. When I show the interface > asynchronous 1 under the ospf, I find that: no hellos (passive interface). > What is mean? >
OSPF Hellos are supressed over a dial-on-demand routing circuit. > Why? can not explain it. Can you help me? Reason - the only information that should travel over the demand circuit are real data and routing changes. Once the link is up, OSPF assumes it's reliable and suppresses Hello's so that the Hello's don't cause the circuit to stay up all the time. If you have Internet access, search the Cisco website (www.cisco.com) for OSPF Design Guide for a more detailed explanation of demand circuits and virutal links and other important OSPF qualities. _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=28708&t=28666 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
