EIGRP summary route redistribution

daan5000daan5000 Member Posts: 34 ■■■□□□□□□□
in CCNP
Hi there,

I'm trying to redistribute an EIGRP summary route into an OSPF 'backbone' network. The redistribution succeeds but my edge router advertises full routes instead of a summary route.

This is my lab configuration:



This is the running config om R8 (EIGRP edge router)
!
hostname R8
!
interface FastEthernet1/0
 ip address 172.16.2.4 255.255.255.248
 ip summary-address eigrp 1 192.168.0.0 255.255.0.0 90
 duplex auto
 speed auto
!
router eigrp 1
 redistribute ospf 1 metric 40000 1000 255 1 1500
 network 192.168.0.0
 auto-summary
!
router ospf 1
 log-adjacency-changes
 redistribute eigrp 1 subnets
 network 172.16.2.0 0.0.0.255 area 0
!

This is the routing table of R1:
172.16.0.0/29 is subnetted, 1 subnets
C       172.16.2.0 is directly connected, FastEthernet1/0
     10.0.0.0/8 is variably subnetted, 6 subnets, 3 masks
R       10.0.2.0/24 [120/1] via 10.0.0.1, 00:00:27, Serial0/0
R       10.0.0.2/31 [120/1] via 10.0.0.4, 00:00:08, Serial0/1
                    [120/1] via 10.0.0.1, 00:00:27, Serial0/0
C       10.0.0.0/31 is directly connected, Serial0/0
O       10.0.0.0/8 is a summary, 00:29:11, Null0
R       10.0.1.0/24 [120/1] via 10.0.0.4, 00:00:08, Serial0/1
C       10.0.0.4/31 is directly connected, Serial0/1
     192.168.0.0/31 is subnetted, 3 subnets
[COLOR=#ff0000]O E2    192.168.0.0 [110/20] via 172.16.2.4, 00:28:17, FastEthernet1/0[/COLOR]
[COLOR=#ff0000]O E2    192.168.0.2 [110/20] via 172.16.2.4, 00:28:17, FastEthernet1/0[/COLOR]
[COLOR=#ff0000]O E2    192.168.0.4 [110/20] via 172.16.2.4, 00:28:19, FastEthernet1/0[/COLOR]

The red lines should be summarized in one route.

I'm studying both CCNA and CCNP, so I hope I'm posting this in the right forums.

Thanks.
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Comments

  • fredrikjjfredrikjj Member Posts: 879
    Redistribution is done from the routing table. You are sending the summary to another router, and it won't be in R8's routing table as an eigrp route. Also, doing an eigrp summary on fa1/0 on R8 (I assume that this link goes to R1), doesn't really make sense if R1 is running OSPF. To achieve your desired result you could create a static route to null0 on R8 and then redistribute that into OSPF, or you could just redistribute the static discard route that's there from the eigrp summary.
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  • networker050184networker050184 Mod Posts: 11,962 Mod
    What EIGRP routes are going to be in R8s routing table? Remember redistribution pulls the routes from the routing table.

    EDIT: fredrikjj beat me to it!
    An expert is a man who has made all the mistakes which can be made.
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  • Dieg0MDieg0M Member Posts: 861
    Hah was gonna post but it's always good idea to refresh before to see if someone beat you to it!
    Follow my CCDE journey at www.routingnull0.com
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  • fredrikjjfredrikjj Member Posts: 879
    I won! icon_cheers.gif


    PS.
    And Diego, you should be studying, not posting on the forum icon_lol.gif
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  • mrjoshuapmrjoshuap Member Posts: 8 ■□□□□□□□□□
    When you are redistributing routes from an external network into the OSPF routing process and you need them summarized in OSPF, you should use the summary-address followed by the summary address and mask under the OSPF routing process. E.g

    router ospf 1
    summary-address 192.168.0.0 255.255.255.248

    Hope that help.

    Thanks.
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  • networker050184networker050184 Mod Posts: 11,962 Mod
    That is not going to help in this scenario.
    An expert is a man who has made all the mistakes which can be made.
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  • daan5000daan5000 Member Posts: 34 ■■■□□□□□□□
    fredrikjj wrote: »
    Redistribution is done from the routing table. You are sending the summary to another router, and it won't be in R8's routing table as an eigrp route. Also, doing an eigrp summary on fa1/0 on R8 (I assume that this link goes to R1), doesn't really make sense if R1 is running OSPF. To achieve your desired result you could create a static route to null0 on R8 and then redistribute that into OSPF, or you could just redistribute the static discard route that's there from the eigrp summary.

    Okay, I tried this and it works. Doesn't EIGRP support redistribution of summary routes like OSPF and RIPv2 do?

    Thanks for your help :)
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  • daan5000daan5000 Member Posts: 34 ■■■□□□□□□□
    mrjoshuap wrote: »
    When you are redistributing routes from an external network into the OSPF routing process and you need them summarized in OSPF, you should use the summary-address followed by the summary address and mask under the OSPF routing process. E.g

    router ospf 1
    summary-address 192.168.0.0 255.255.255.248

    Hope that help.

    Thanks.

    Not sure, but I think this is used to send an OSPF summary route into another routing protocol. I need to redistribute an EIGRP summary route into OSPF, the other way round.

    Thanks for your help though.
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  • networker050184networker050184 Mod Posts: 11,962 Mod
    daan5000 wrote: »
    Okay, I tried this and it works. Doesn't EIGRP support redistribution of summary routes like OSPF and RIPv2 do?

    Thanks for your help :)

    Yes it does, but when you create a summary route on a router it is not in that routers routing table, it is advertised out. With redistribution you need a route in the routers routing table that is doing the redistribution.
    An expert is a man who has made all the mistakes which can be made.
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  • mrjoshuapmrjoshuap Member Posts: 8 ■□□□□□□□□□
    Yeah, you are correct, i stand corrected i didn't fully understand the question. This is good to know.
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