Hunt Lee wrote: > > I have an EIGRP question that I'm a bit confused: > > Firstly, let me try to see if I understand the terms: (for > EIGRP) > > Successor - A neighoring router used for packet forwarding that > has a least > cost path to a destination. > > Feasible Successor - Next-hop router for the backup path. > > > If this is the case, on TCP / IP Vol 1 (by Doyle) at p342 Fig > 8.8 > > It shows the following EIGRP topology table:- (for Router > Chanute) > > Chanute# show ip eigrp topology > > P 10.1.6.0 /24, 1 successors, FD is 768 > via 10.1.2.1 (768 / 512), Ethernet0 > > First number (768) is the Feasible Dist of this local router > (Chanute), > while the second number is the Advertised Dist from the > neighbor router (at > 10.1.2.1) > > Since the first number equals the FD, this 10.1.2.1 is a > successor for > subnet 10.1.6.0 /24. However, Jeff said "the route to 10.1.6.0 > has an FD of > 768 (which I agree so far), and Wright (at 10.1.2.1) is the > only feasible > successor. ??? > > But isn't 10.1.2.1 the successor rather than the feasible > successor?
Yes, I think you are correct. This is a fairly common use of terminology though. If a successor stands alone, it also by default is the only *feasible* successor. You could just as well debate the definition of "synchronous." > > > As another example: (for another router called Langley) > > Langley# show ip eigrp topology > > P 10.1.2.0 /24, 1 successors, FD is 768 > via 10.1.3.1 (768 / 256), Serial 0 > via 10.1.5.2 (1280 / 256), Serial 1 > > In this case, since the route via 10.1.3.1 has FD have 768, it > will be the > successor, > > and the route via 10.1.5.2 has FD have 1280 (which is > 768) - > so it is a > feasible successor > > Am I on the right track? I don't think so. I think that DUAL requires that the AD of the FS be less than the FD via the successor. Now if you are just asking whether or not the fact that the FD is higher makes it a FS instead of a full-fledged successor, I would sort of agree. But the loop-prevention aspect of DUAL needs to be met before a route becomes a FS. > > Time to go home.... > > Thanks for any help in advance, > > Best Regards, > Hunt Lee > System Engineer > WebCentral > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=36076&t=36044 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
