EIGRP Question ...

Unanswered Question
May 16th, 2007
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Hi,

I would just like to confirm this scenario ....


Router A is running EIGRP with AS number 20 and is advertising network 172.11.0.0

in its EIGRP.


The configuration is as follows :-

router eigrp 20

netwrok 172.11.0.0

no auto-summary


Router B is another router that is connected to Router A and its configuration is as follows :-


router eigrp 20

netwrok 172.11.0.0

network 10.192.112.0

no auto-summary


My question is that [1] Router A would know network 10.192.112.0 since it would be advertised to it by Router B right ?


[2] It is redundant to advertise network 10.192.112.0 in router A right ? It is okay to do so but it is not necessary as router B would advertise this network to Router A isn't it ...


Pls advice,


Thank you,


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Overall Rating: 4 (3 ratings)
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mohammedmahmoud Wed, 05/16/2007 - 03:29
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Hi,


[1] yes, EIGRP should do this.


[2] I can't get what you mean, but any way as long as router B sends it to router A, router A will advertise it to any other connected routers.


NOTE: Network command should be used to advertise direct connected interfaces, thus it can't be done on router A, as this IP is not for an interface connected to router A.


HTH, please do rate all helpful replies,

Mohammed Mahmoud.

Jon Marshall Wed, 05/16/2007 - 03:35
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Hi


Just to add to Mohammed's post. By entering 172.11.0.0 under the EIGRP confgiuration you are not telling EIGRP to advertise the 172.11.0.0 network. You are telling EIGRP on which interfaces to start EIGRP on.


Hence Mohammed's point about if there is no interface you shouldn't include the network statement under EIGRP.


HTH


Jon

mohammedmahmoud Wed, 05/16/2007 - 03:40
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Hi,


Jon is totally right, always keep in mind that the network command for all routing protocols (except BGP) is used to tell the routing process which interface shall it run on and send in its updates (but note that the updates will use the subnet mask of the interface not the subnet mask of the network command).


HTH,

Mohammed Mahmoud.

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