842-902 on Aaron's Worthless Words

ROUTE Notes - OSPF Topology Stuff

Sun, 20 Jun 2010 00:00:00 +0000

Feel free to correct.

Study Questions

The obvious first question involves the common LSA types and their function. Can you list them?

Type-1 - Router - Lists each router their connected IP addresses Type-2 - Network - Lists all the transit, or multiaccess, networks Type-3 - Net Summary - Defines a host route for interarea routes; this is from the ABR Type-4 - ASBR Summary - Defines a host route for an external (to OSPF) route; this is from an ASBR Type-5 - AS External - Lists the networks advertised into OSPF from external sources (redistribution) Type-7 - NSSA External - External routes injected into a not-so-stubby area

ROUTE Notes - EIGRP Topology Stuff

Thu, 17 Jun 2010 00:00:00 +0000

Study Questions

How do you keep EIGRP from killing your WAN?

You can use the ip bandwidth-percent eigrp AS X command to limit the amount of bandwidth that EIGRP uses to update neighbors.

How does EIGRP calculate how much bandwidth it can use for each frame relay PVC?

By default, EIGRP takes 50% of the (sub)interface’s configured bandwidth (with the bandwidth command) to use for updates on NBMA (non-broadcast mutliaccess) networks like frame relay. This value is divided equally among all the PVC configured on that interface.

ROUTE - Redistribution Nuance #2 - OSPF External Metric Types

Sun, 06 Jun 2010 00:00:00 +0000

Last time, we talked about a nifty little lab I set up for redistribution and how the OSPF ASBRs acted a little differently than I expected. This time, let’s look at how changing external OSPF routes to a metric-type of 1 (E1) affects the routing tables.

Here’s the network again.

The static routes are being redistributed into their respective IGPs, and EIGRP is being redistributed into OSPF. Let’s look at the routing table on R1.