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New Member

redistribute eigrp into bgp

I have two data centers that have a one gig fiber link between both of the cores that the data centers

(3750's) we run eigrp in our network. At data center 1 i have a 7206 with a 100MB sprint mpls link that runs BGP between it and our remote sites. I have setup mutual eigrp-bgp redistribution so that the remote sites get eigrp routes in BGP and my datacenter get the BGP routes in to EIGRP. Now at datacenter 2 i also have a 7206 with a 10MB sprint mpls link that i want to uses as a backup. The problem as soon as i setup bgp it get the routes from BGP and they take over the EIGRP routes and now all my traffic goes over that 10MB Link to datacenter 1 and not the 1gig that is on the cores. anyone have something like this setup?

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15 REPLIES
Hall of Fame Super Blue

Re: redistribute eigrp into bgp

christopherjensen wrote:

I have two data centers that have a one gig fiber link between both of the cores that the data centers

(3750's) we run eigrp in our network. At data center 1 i have a 7206 with a 100MB sprint mpls link that runs BGP between it and our remote sites. I have setup mutual eigrp-bgp redistribution so that the remote sites get eigrp routes in BGP and my datacenter get the BGP routes in to EIGRP. Now at datacenter 2 i also have a 7206 with a 10MB sprint mpls link that i want to uses as a backup. The problem as soon as i setup bgp it get the routes from BGP and they take over the EIGRP routes and now all my traffic goes over that 10MB Link to datacenter 1 and not the 1gig that is on the cores. anyone have something like this setup?

Christopher

A quick topology diagram showing the relevant connections routers would definitely help.

Jon

New Member

Re: redistribute eigrp into bgp

I have uploaded a pic of the basic setup. I want to bring up the 10mb m

pls but still have the traffic between the 2 7206 routers go over the gigbit att fiber and not the 10

mb mpls as it is slow and only for backup.

Hall of Fame Super Blue

Re: redistribute eigrp into bgp

Christopher

Apologies, i don't have visio. Could you possibly post it as a .jpg ?

Jon

New Member

Re: redistribute eigrp into bgp

Sure here it is in jpg.

Hall of Fame Super Blue

Re: redistribute eigrp into bgp

Chris

Manish has a good point but just to clarify are you redistributing BGP into EIGRP in DC2. If not then how is the traffic in DC2 going via the 10Mbps link ie. is the default-gateway in DC2 set to BGP router ?

I know BGP has lower AD than EIGRP but unless the traffic is set to BGP router in DC2 and not 375 why is it taking that route.

Jon

New Member

Re: redistribute eigrp into bgp

Yes i want to redistribute BGP into EIGRP at DC2 and also EIGRP into B

GP incase the DC1 sprint mpls goes down. I have other point to points and things coming into the 7200's at each data center. When i try and setup DC2 the same way as DC1 the traffic that is coming into DC2 7200 from a point to point goes accross the 10mb mpls and not the 1 gig core links. i know its because BGP has a AD of 20 and EIGRP is 90 but i am not sure on the best way to setup DC2 with Eigrp and BGP so that it only using that if the sprint mpls goes down at DC1.

Hall of Fame Super Blue

Re: redistribute eigrp into bgp

christopherjensen wrote:

Yes i want to redistribute BGP into EIGRP at DC2 and also EIGRP into B

GP incase the DC1 sprint mpls goes down. I have other point to points and things coming into the 7200's at each data center. When i try and setup DC2 the same way as DC1 the traffic that is coming into DC2 7200 from a point to point goes accross the 10mb mpls and not the 1 gig core links. i know its because BGP has a AD of 20 and EIGRP is 90 but i am not sure on the best way to setup DC2 with Eigrp and BGP so that it only using that if the sprint mpls goes down at DC1.

But that's the confusing bit. BGP will only take priority over EIGRP on the actual BGP router. The 3750 switch in DC2 will not have any BGP. So is the 3750 in DC2 acting as a L2 or L3 switch ?

And when you say traffic goes over the 10Mbs link traffic from where ie. a server in DC2. If it is a server in DC2 what is it's default-gateway ie. the BGP router in DC2, the 3750 switch (if it is acting as L3) or another L3 device not shown.

If the 3750 switches are L2 only is there any reason you can't make them L3 and make them the default-gateway for devices in DC2. Then you can redistribute EIGRP into BGP in DC1 and DC2 but apply an offset-list to the EIGRP routes from BGP DC2 router so preferred path from DC2 is via the 100Mbps link using the EIGRP routes learn from DC1.

Jon

New Member

Re: redistribute eigrp into bgp

Sorry traffic between datacenters go over the 3750's layer 3 just fine. The problem comes in that the 7200's at both DC's have more then just the sprint mpls they have T1's to other point to point sites. so lets say site 1 comes in on a att t1 point to point to DC2 and needs to get something from DC1 it then sends that traffic over the mpls to DC1 and not over the 3750 link.

Hall of Fame Super Blue

Re: redistribute eigrp into bgp

christopherjensen wrote:

Sorry traffic between datacenters go over the 3750's layer 3 just fine. The problem comes in that the 7200's at both DC's have more then just the sprint mpls they have T1's to other point to point sites. so lets say site 1 comes in on a att t1 point to point to DC2 and needs to get something from DC1 it then sends that traffic over the mpls to DC1 and not over the 3750 link.

Ahh okay now i understand. Can you just confirm that BGP DC2 router learns EIGRP routes for DC1 via the 100Mbps link ?

If so you could play around with ADs on the BGP router so that the EIGRP learned routes via the 3750 L3 switch are preferred over the BGP learnt routes. You would need to lower the AD of the EIGRP routes to below AD 20 or increase the AD for BGP learnt routes.

Jon

New Member

Re: redistribute eigrp into bgp

Yes the DC2 Router does get EIRP from the 3750. The problem is like you said when i turn up the BGP for the MPLS the AD on the BGP is lower and takes over the EIGRP routes.  Do you by chance have a example on how i make the AD lower for EIGRP on that router?

Thanks

Re: redistribute eigrp into bgp

Hall of Fame Super Blue

Re: redistribute eigrp into bgp

Chris

http://www.cisco.com/en/US/docs/ios/iproute_eigrp/command/reference/ire_a1.html#wp1058942

Note is the external EIGRP AD you need to be lower than AD 20.

Jon

Hall of Fame Super Blue

Re: redistribute eigrp into bgp

Chris

Just quick addition -

you may need to have the internal value lower than the external value altho i'm not sure ie. the router might complain if you have a lower value for external EIGRP than internal EIGRP. Not a problem if it does just make it lower than your modified exetrnal value. Your not using internal EIGRP routes on that router anyway as far as i can tell.

Jon

Re: redistribute eigrp into bgp

Ummm .. Run two different AS for Eigrp and redistribute both into the BGP cloud , also make sure that you increase AD on the EIGRP 10 mb AS to more than 170 then those routes will act as backup and traffic will flow through the primary EIGRP AS with default 170 AD. I think if you search online for a similar senario where you play with AD to get the routing policy you need.

Thanks

Manish

New Member

Re: redistribute eigrp into bgp

hi,

1. The sites which is connected to your DC2 7200 router via point to point , if it try to reach your DC1 server it should go via your 1 gig link and it should not use your 10 Mbps mpls link. is this your requirement ?

2.  what is the AS number you are using for DC1 DC2 and remote sites connected to mpls cloud.  Is it the same AS number or different AS number.

Regards,

Hariharan k

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