EIGRP Route Selection

[sanjay.khurana]

Hi,

I have Core switch which connected to 2 wan router and i am getting defautl route from both router  but my wan router is select one as best path.

Routeing protocol is EIGRP , Is load is factor to makeing best path selection in DUAL algorithm of EIGRP. here my query is why my core switch is taking VLAN 951 as best path for default route

    sh ip route 0.0.0.0

Routing entry for 0.0.0.0/0, supernet

  Known via "eigrp 1", distance 170, metric 258562816, candidate default path

  Tag 99, type external

  Redistributing via eigrp 1

  Last update from 10.130.95.250 on Vlan955, 4d00h ago

  Routing Descriptor Blocks:

* 10.130.95.234, from 10.130.95.234, 4d00h ago, via Vlan951

      Route metric is 258562816, traffic share count is 1

      Total delay is 100110 microseconds, minimum bandwidth is 10 Kbit

      Reliability 255/255, minimum MTU 1500 bytes

      Loading 115/255, Hops 2

    10.130.95.250, from 10.130.95.250, 4d00h ago, via Vlan955

      Route metric is 258562816, traffic share count is 1

      Total delay is 100110 microseconds, minimum bandwidth is 10 Kbit

      Reliability 255/255, minimum MTU 1500 bytes

      Loading 1/255, Hops 2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

sh ip eigrp topology 0.0.0.0

IP-EIGRP topology entry for 0.0.0.0/0

  State is Passive, Query origin flag is 1, 2 Successor(s), FD is 258562816

  Routing Descriptor Blocks:

  10.130.95.250 (Vlan955), from 10.130.95.250, Send flag is 0x0

      Composite metric is (258562816/258562560), Route is External

      Vector metric:

        Minimum bandwidth is 10 Kbit

        Total delay is 100110 microseconds

        Reliability is 255/255

        Load is 1/255

        Minimum MTU is 1500

        Hop count is 2

      External data:

        Originating router is 10.190.0.1 

        AS number of route is 65000

        External protocol is BGP, external metric is 0

        Administrator tag is 99 (0x00000063)

        Exterior flag is set

  10.130.95.234 (Vlan951), from 10.130.95.234, Send flag is 0x0

      Composite metric is (258562816/258562560), Route is External

      Vector metric:

        Minimum bandwidth is 10 Kbit

        Total delay is 100110 microseconds

        Reliability is 255/255

        Load is 115/255

        Minimum MTU is 1500

        Hop count is 2

      External data:

        Originating router is 10.190.32.1 

        AS number of route is 65000

        External protocol is BGP, external metric is 0

        Administrator tag is 99 (0x00000063)

        Exterior flag is set

[IAN WHITMORE]

Is your maximum-paths set to 1 ?

Regards,

Ian

[sanjay.khurana]

@Lan

No we are not using this command into EIGRP process.

[IAN WHITMORE]

Wee  EIGRP uses a composite metric, meaning it’s made up of several smaller metrics:

• Bandwidth (minimum along path)
• Delay (cumulative along path)
• Reliability
• Load
• MTU

So it CAN take load into consideration but usually the k values for load and MTU are set to 0.

Here is a guide for you to take a look at to check this:

http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094cb7.shtml

There is nothing in your log to indicate anything?

Regards,

Ian

[sanjay.khurana]

What logs  I need to capture to make perfect understanding ?

[cadet alain]

Hi,

You should be doing equal cost load balancing as  your metrics are equal and load is not used in the metric calculation  otherwise the metrics would have been different.

The only way I know to disable load balancing is to put  a  max path of 1 as iwithmore suggested.

Just enable logging on console and monitor and you should be good to go.

Can you post your running.

Regards.

Alain.

[sanjay.khurana]

we are not using load-balancing in EIGRP , may be it's taking by default ..and i can not post sh runn here due to some security you tell me what you need i will try my best to post that section of sh runn.

[cadet alain]

Hi,

we are not using load-balancing in EIGRP

By default all routing protocols and static routes do equal cost load-balancing.

Here you have two equal cost(same feasible distance==metric) paths for your default route redistributed by BGP.

So you should be doing load-balancing  and you complained it was not the case in your initial post.

For your config , change your IP or mask some octets and for your passw just don't post it.Will still there be confidential infos left?

Alain.

Regards.