Category Archives: 1.3 EIGRP

Stub Routers:As we learned in 1.3.c iii, routes hang out in the active state waiting for a reply to the query they sent. What if we know for sure that the route we’re trying to learn about is definitely not down that alley behind that building over there. Do we really need to send queriesContinue reading “1.3.f v EIGRP stub with leak map”

Optimization comes down to three things: Failure detection: How fast can we figure out something’s wrong? (We should use BFD here, but let’s pretend we can’t because the task tells us not to.) Information propagation: How fast can we tell our neighbors about the failure? Fault repair: How fast can we calculate an alternate path?Continue reading “1.3.f Optimization, convergence and scalability (EIGRP)”

Updated 11/5/23 to include unicast vs multicast neighbors and the no next-hop-self command.The nice thing about Named Mode is everything is (sort of) in the same place, instead of some config being under router eigrp and some config being under individual interface configs. Is that it, it’s just more organized? There are also these advantages:Continue reading “1.3.e EIGRP Named Mode”

1.3.d i Equal-cost Enabled by default, as long as the metrics match. Nothing really to do here. 1.3.d ii Unequal-cost Use the variance command. The only trick is when you multiply your best path’s metric by the configured variance, the product has to be higher than any potential path’s metrics, otherwise they still won’t beContinue reading “1.3.d EIGRP load balancing”

A quick look at our topology: Let’s set up a summary route for the following loopbacks on R20. R20interface lo104 ip add 10.10.104.1 255.255.255.0interface lo105 ip add 10.10.105.1 255.255.255.0interface lo106 ip add 10.10.106.1 255.255.255.0interface lo107 ip add 10.10.107.1 255.255.255.0 router eigrp 10 network 10.10.104.0 0.0.0.255 network 10.10.105.0 0.0.0.255 network 10.10.106.0 0.0.0.255 network 10.10.107.0 0.0.0.255 SummarizationContinue reading “1.3.f iv Leak-map with summary routes (EIGRP)”