Pete's Packet

RIP notes

1. ip summary-address will suppress more specific routes in RIP. So you do not have to configure an distribute-list.
2. watch the tasks wording.
3. configure RIP for unicast ONLY you need a neighbor statement (to enable unicast) and you need to disable broadcast / multicast by using passive-interface.
4. ran into an issue with authentication failed after changing from md5 to text authentication. I removed the authentication config under the interface and readded it and it started working.
5. req: send updates out necessary interfaces only, loop0 sneaked in there for me. Found it by change by using debug ip rip events. solution: config passive for the loopbacks.
6. when changing metrics with an offset-list config the offset-list close to the source. I got it to work on the closest router with in/out and on the router that needed to see the metric with offset in. All solutuions worked no restrictions based on the task.
7. req: prepare for a futute vlan (secondary address on an interface) solution: disable ip split-horizon or no validate update source on the other router.
8. when connecting to non-cisco devices you need to disable to holddown. timers basic 30 180 0 240

Q. How is IP split horizon handled on Frame Relay interfaces?

A. IP split horizon checking is disabled by default for Frame Relay encapsulation to allow routing updates to go in and out of the same interface. An exception is the Enhanced Interior Gateway Routing Protocol (EIGRP) for which split horizon must be explicitly disabled.

Configuring Frame Relay subinterfaces ensures that a single physical interface is treated as multiple virtual interfaces. This capability allows you to overcome split horizon rules so packets received on one virtual interface can be forwarded to another virtual interface, even if they are configured on the same physical interface.