But what if a route's metric changes, so that the minimum distance to the destination increases beyond the FD. In this case will the FD be updated or not?
If the answer is yes, (as I assume it to be) why does Dyole say that because the route didn't become active the FD didn't change.(Chapter 8, before figure 8.15) Thanks, Hamid --- "Steven A. Ridder" wrote: > The FD is the lowest distance a router has to a specific network. > A router > may have more than one path to said network, but the lowest > distance is FD > and it is entered into the routing table. More than one route to > said > network can still exist and it will be entered in the EIGRP > topology table > as a back-up route. > > Without reading of the examples, I am guesing that a route's metric > in the > EIGRP topology table has changed. Even if it goes lower than it > was > previously, if it's not lower than the FD (the route in the routing > table) > than the FD to that netwtork doesn't change. If it is lower, than > it will > change the FD as it will become the new FD. > > -- > > RFC 1149 Compliant. > Get in my head: > http://sar.dynu.com > > > ""Hamid Ali Asgari"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Hi, > > > > Studying EIGRP, I got to a question: When is the Feasible > Distance > > (FD) for a destination updated. In Jeff Doyles Routing TCP/IP, > > chapter 8, it says that as a result of a local computation the > > following may occur: > > > > -If the feasible successor with the lowest distance is different > from > > the existing successor, the feasible successor will become the > > successor. > > -If the new distance is lower than the FD, the FD will be > updated. > > -If the new distance is different from the existing distance, > updates > > will be sent to all neighbors. > > > > So I asume that as a result of a local computation the FD may be > > updated (reduced). > > > > Later in this chapter, before figure 8.15 it says: Because the > > distance to 10.1.7.0 has increased and the route did not become > > active, the FD is unchanged at Lilienthal. > > > > In EIGRP's White Paper on cisco's web site, after figure 3 it > says: > > When the link between Routers One and Three goes down, Router One > > examines each path it knows to Network A and finds that it has a > > feasible successor through Router Four. Router One uses this > route, > > using the metric through Router Four as the new feasible > distance. > > > > In the book , Network Design and Case Studies by Cisco , Chapter > 3 > > Designing Large Scale Ip netwoks, Subtitle : Enhanced EIGRP > > Convergence , It is mentioned that the > > FD can only change during an active-to-passive transition . > > > > I am totally confused about the FD and what triggers an update > for > > it. I don't get it. Is a ROUTE ACTIVATION required for a FD > update > > necessarily? > > > > If the router receives a better advertisement , and if the FD is > > lower , I feel FD can change during a local computation itself . > > > > Could any one explain? > > > > Thanks in advance, > > > > Hamid > > > > __________________________________________________ > > Do You Yahoo!? > > Yahoo! Greetings - send holiday greetings for Easter, Passover > > http://greetings.yahoo.com/ [EMAIL PROTECTED] __________________________________________________ Do You Yahoo!? Yahoo! Greetings - send holiday greetings for Easter, Passover http://greetings.yahoo.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39978&t=39978 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
