redistribution, and default metric in eigrp

[sarahr202]

Hi every body

I understand when we redistribute  routes say from ospf into eigrp  , we have to configure metric so that eigrp can perform its calulation in selecting the best route.

However,  when we distribute Static routes into eigrp, we don't  need to configure metric.  My question   is what is the default bandwidth and delay considered to  compute the  advertised distance before a router can advertise it to its neighbor .

thanks  and have a great weekend.

[Thotsaphon Lueangwattanaphong · Accepted solution]

Hi,

   You need to define metrics for static routes redistributed into eigrp. There is no default-metric. You need to do metric conversion. You won't need to define when redistributing from eigrp to other eigrp process. You can define a default-metric for other protocols redistributed into eigrp.

For example

!

router eigrp 100

redistribute ospf 1

redistribute static

default-metric 10000 100 255 1 1500

!

HTH,

Toshi

[sarahr202]

Hi Toshi.

thanks for your  response

My understanding  is  we can redistribute  static routes into eigrp  without configuring  metric.  Metric  must be configured for  all protocols being  redistributed into eigrp  otherwise redistribution will not occur.

thanks and have a great weekend

[naveed817 · Accepted solution]

Hi,

The static routes are like directly connected interfaces, even if your issuing the command redistribute static, only AD will be changed as it will be advertise as an external network

Also whenever you will advertise this network to other eigrp neighbors it will use the interface parameters to calculate the bandwidth where its neighbour is connected.

Hope you understand what i mean. Its same as you are redistributing connected networks.

Regards,

Naveed Shahzad

[sarahr202]

Thanks for your reply.

Let  say we have three routers;

          199.199.199.0/24                200.200.200.0/24                           10.10.10.10/8

R1 s0----------------------------s0 R2 s1-------------------------------------------- s1 R3-------------- layer 2 sw

R3 is running eigrp only on s1

R2 is configured with static route as:

ip route 10.0.0.0 255.0.0.0  200.200.200.3  (  the ip address of s1 on R3)

Now   when  redistribute static on R2,   R2 will advertise this with as an external route and with a metric to R1.  The question is   what bandwidth and delay values this metric  will have ?

You mentioned metric will carry  bandwidth and delay  of interface. which interface?  you mean S1 on R2 or?

thanks for your help.

[Thotsaphon Lueangwattanaphong · Accepted solution]

Hi Sarahr,

    First off,my first reply was wrong. I apologized for that.  Seems I have to gid rid of (obsolete) things on my head again.

    Well, your topology is okay to reveal this problem.

    R2 will use bandwidth and delay on Serial0 for a static route redistributed into Eigrp. You can check this by enabling 199.199.199.0/24 on Serail0 in Eigrp.

    And then you can compare things.

Router#show ip eigrp topology 199.199.199.0 255.255.255.0

      Composite metric is (YYYYY/0), Route is Internal
      Vector metric:
        Minimum bandwidth is AAAA Kbit
        Total delay is BBBB microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 0

Router#show ip eigrp topology 10.0.0.0 255.0.0.0

      Composite metric is (YYYYY/0), Route is External
       Vector metric:
         Minimum bandwidth is AAAA Kbit
         Total delay is BBBB microseconds
         Reliability is 255/255
         Load is 1/255
         Minimum MTU is 1500
         Hop count is 0

       You should see the same thing on both routes.  You can modify bandwidth of Serial0 and see what happens on both routes. YYYYY is the metric that R2 advertises to R3.

HTH,

Toshi

[Kishore Chennupati · Accepted solution]

Hi sarahr202,

In your case whatever is the outgoing interface on R2 towards R3.You can see from the "sh ip eigrp top 10.0.0.0/8" on R2 and you can see the metric. you will see something like below if the interface is a gigabit.

R1#sh ip eigrp top 10.0.0.0/8
:  192.168.2.2, from Rstatic, Send flag is 0x0
      Composite metric is (2816/0), Route is External
      Vector metric:
        Minimum bandwidth is 1000000 Kbit
        Total delay is 10 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 0

And you were right earlier that you dont need to explicitly define metric for static and connected when you redistribute.

HTH,

Regards

Kishore