tag:blogger.com,1999:blog-5968686435283454526.post4575058863899167522..comments2024-03-10T21:40:55.615-07:00Comments on Jeff Kronlage's CCIE Study Blog: [mini] OSPF Point-to-Multipoint .... Multicast?brbcciehttp://www.blogger.com/profile/14586635047530183862noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-5968686435283454526.post-43298579367123079922017-08-13T20:07:09.401-07:002017-08-13T20:07:09.401-07:00This comment has been removed by a blog administrator.sena nabilahttps://www.blogger.com/profile/09424258106271201408noreply@blogger.comtag:blogger.com,1999:blog-5968686435283454526.post-8336338682299808202014-01-12T17:30:44.345-08:002014-01-12T17:30:44.345-08:00i believe the whole point of multicast in a broadc...i believe the whole point of multicast in a broadcast environment is it's ability to discover neighbors and also choose one centralized router as a DR to exchange updates with instead of ramming the segment with updates in all directions, i also believe that multicast is used in cases when ip unnumbered interface is used on point to point links since it's impossible for the router to figure out which IP address it's peer is using, so it'll send and listen to multicast 224.0.0.5 until this is resolved. and yes, it has to be done in lab'd and sniffed :)Shereif ElHamalawyhttps://www.blogger.com/profile/04894554475081834993noreply@blogger.comtag:blogger.com,1999:blog-5968686435283454526.post-1417748374570945172014-01-12T17:21:29.155-08:002014-01-12T17:21:29.155-08:00I'd be surprised if that were the case in a br...I'd be surprised if that were the case in a broadcast environment - although I could see it being potentially true in point-to-point? Lab it and let us know!brbcciehttps://www.blogger.com/profile/14586635047530183862noreply@blogger.comtag:blogger.com,1999:blog-5968686435283454526.post-75860109196265568352014-01-12T17:18:57.997-08:002014-01-12T17:18:57.997-08:00before i comment, don't press the damn preview...before i comment, don't press the damn preview button to check your comment! you'll lose everything you typed<br /><br />back to topic, i was just talking to a friend of mine today about this today. the thing is (regardless of OSPF interface type) , OSPF uses multicast to discover neighbors and to bring neighborship up, but as soon as OSPF master/slave negotiation is settled, OSPF uses unicast packets to exchange updates. i believe OSPF uses unicast packets from the start if you inserted the neighbor command under the OSPF router configuration, since it doesn't need to automatically discover it's neighborShereif ElHamalawyhttps://www.blogger.com/profile/04894554475081834993noreply@blogger.com