The same equally applies to a real l2-switched (and wired) network (vs. emulated by VPLS), as pointed out earlier by Pete [[email protected]]:
> There is also a case of multiple ethernet switches connected together > serially, with varying propagation delays to the routers that are connected > to one of these switches. Imagine different types of transmission > technologies in the network but still having ethernet on each end of the > links. > From the perspective of a router connected to the nearest switch, a router on > a far end switch will have higher propagation delay than a router connected > to the same (nearest) switch, so having the ability to define a higher OSPF > metric to that far end router can become important. Jeffrey > -----Original Message----- > From: Nischal Sheth [mailto:[email protected]] > Sent: Wednesday, February 09, 2011 3:14 PM > To: [email protected] > Cc: Jeffrey (Zhaohui) Zhang; Alvaro Retana (aretana); Acee Lindem > Subject: Re: [OSPF] OSPF Hybrid Broadcast and P2MP Interface Type > > On 1/6/2011 2:05 PM, Jeffrey (Zhaohui) Zhang wrote: > > > > > Additionally, while radio network is one example, it is not > the only one. > > > > Here's a different example that highlights Jeffrey's point above. > > If a Service Provider's OSPF is running over a broadcast > network that is > emulated by a VPLS service, it is useful to advertise a > different OSPF > metric for each neighbor on the broadcast network. This > allows you to > achieve nearest exit routing when transiting the VPLS backbone for > customers that are dual homed to the SP via BGP. > > The metric for each neighbor could be manually configured. > Modeling the > LAN as a hybrid interface lets you use the DR and DBR for flooding as > opposed to treating it as p2mp in OSPF and establishing a > full mesh of > adjacencies. > > -Nischal > > _______________________________________________ OSPF mailing list [email protected] https://www.ietf.org/mailman/listinfo/ospf
