...what is an NBMA network? As the name implies, an NBMA network supports access from multiple routers at the same time but doesn’t support broadcast packets. For example, frame relay multipoint networks allow a single IP subnet to be shared by multiple routers in a partial or full mesh topology. Although each router shares an IP subnet with the other routers across the frame relay cloud, they cannot send a single broadcast packet and have it simultaneously delivered to all the other routers on that subnet. Instead, the pseudobroadcast packets would need to be replicated and sent to each neighbor independently.
he should change his name to russ blonde...
and just in case:
split horizon...
The split-horizon rule states that a router should not advertise destinations out the interface it is using to reach those destinations.
also, it is important that you use the correct command to disable split horizon in eigrp, see below (i ran into this over the weekend when i was trying to see all links, show ip eigrp topo all-links, and they weren't showing up)...
you might think that the command
no ip split-horizon
configured on router A’s multipoint serial interface would change the
behavior. In fact, it doesn’t impact EIGRP operation at all! Instead,
you must use the EIGRP-specific command no ip eigrp split-horizon instead. Normally, disabling split horizon is not recommended, but occasionally, a
legitimate need for disabling the default behavior occurs.russ, you're a prince...
one last note here:
do not be mistaken that russ's book on eigrp is only about eigrp... on the contrary, it is about routing in general and is full of gems that will help you with any protocol, including the static protocol... that's correct, he presents the idea of default and static routes as protocols, which may be obvious, but when was the last time you thought of them that way...
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