Hunt Lee wrote: > > I believe someone might have mentioned this already but since > I'm studying > it right now I thought I'd ask again... It would be greatly > appreciated if > someone can shed some light on this. > > For OSPF Point-to-MulitPoint Network type, does the OSPF > packets use > multicast or unicast? > > My understanding is that Point-to-Multipoint Network type is a > special > config of NBMA network in which the network are treated as a > collection of > Point-to-Point links. And since Point-to-Point links always > use multicast > (to ALLSPFRouter address 224.0.0.5), I thought Multicast will > hence use > Multicast too... however... the TCP / IP Vol1 by Jeff Doyle says > Point-to-Point links' Updates as well as Hello packets use > unicast > > Please help... > > Best Regards, > Hunt Lee > >
Hunt Lee, Georg Pauwen has provided an excellent summary. I'm cutting and pasting that into a word document for quick reference in the future. If you have a couple of routers available, I would recommend turning on 'debug ip packet' 'debug ip ospf adj' 'debug ip ospf hello' and 'debug ip ospf packet' Shut and no shut a couple of interfaces here and there. Do this for all types of NMBA modes. You can see where the various traffic types are coming from and going to (e.g. hellos to 224.0.0.5 on p-t-p and p-t-mp subinterfaces), etc. Scott Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=36390&t=36352 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
