eigrp topology table

[Yassin Alizadeh Golbazi]

Hi

Whether in eigrp routes whit 3 hop count don't appear in topology table when we have 2 other route whit lower hop count?

For example i have 3 route to X

r1-r2-X

r1-r3-r2-X

r1-r4-r3-r2-X

And 3th route dont listed in eigrp topology table

Any idea plz

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[Thomas Park]

I think, the reason behind not showing the 3rd route is because the topology table only shows successor and feasible successor. So only two best routes are listed!

You should be able to get the third route on the table,

IMHO, if you configure lower bandwidth on the link between r1 <-> r2

Any other idea?

[Yassin Alizadeh Golbazi]

With "#sh ip ei to all-link" we can see all route even links that is not FS route

But so i cant see 3th route

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[cflory]

Try adding a variance:

variance (EIGRP)

To control load balancing in an Enhanced Interior Gateway Routing Protocol (EIGRP)-based network, use the variance command in router configuration mode. To reset the variance to the default value, use the no form of this command.

variance multiplier

no variance

Syntax Description

multiplier

Metric value used for load balancing. It can be a value from 1 to 128. The default is 1, which means equal-cost load balancing.

Defaults

1 (equal-cost load balancing)

Command Modes

Router configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Setting a variance value lets the Cisco IOS software determine the  feasibility of a potential route. A route is feasible if the next router  in the path is closer to the destination than the current router and if  the metric for the entire path is within the variance. Only paths that  are feasible can be used for load balancing and included in the routing  table.

If the following two conditions are met, the route is deemed feasible and can be added to the routing table:

•The local best metric must be greater than the metric learned from the next router.

•The  multiplier times the local best metric for the destination must be  greater than or equal to the metric through the next router.

Examples

The following example sets a variance value of 4:

router eigrp 109

 variance 4

HTH!

-Chris

[nkarpysh]

Topology only have information of feasible successors. Did you check if your 3rd route satisfy the feasibility condition? If it is not then it will be thrown away. You can check with debug.

Nik

[dslice]

Not true. The topology table contains more than successors and feasible successors. It contains all paths that have been received and not removed by the router sending it.

In answer to the original question, hop count is not a factor until it reaches the max value, which defaults to 100 hops. In order to know why a route doesn't show up, you need to supply the total topology in play and the output of "show ip eigrp topo " for the prefix in question from all routers in the path.

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