redistribution from bgp to eigrp

[julxu]

Hi

I have to ask a siley question:

I need add addtional bgp to eigrp redistribution list  to router eigrp.

this is for ip 10.10.128.0/18 ( just an example)

currently on the router it is two routes existed that is :

>sh ip eigrp top 10.10.128.0/18
EIGRP-IPv4 Topology Entry for AS(1)/ID(10.24.0.254) for 10.10.128.0/18
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2586112
Descriptor Blocks:
10.0.0.1 (Vlan100), from 10.0.0.1, Send flag is 0x0
Composite metric is (2586112/2585856), route is External
Vector metric:
Minimum bandwidth is 1000 Kbit
Total delay is 1020 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 2
Originating router is 10.26.0.254
External data:
AS number of route is 64625
External protocol is BGP, external metric is 0
Administrator tag is 0 (0x00000000)
10.0.2.254 (Vlan102), from 10.0.2.254, Send flag is 0x0
Composite metric is (2586368/2586112), route is External
Vector metric:
Minimum bandwidth is 1000 Kbit
Total delay is 1030 microseconds
Reliability is 255/255
Load is 127/255
Minimum MTU is 1500
Hop count is 3
Originating router is 10.26.0.254
External data:
AS number of route is 64625
External protocol is BGP, external metric is 0
Administrator tag is 0 (0x00000000)

 and local bgp has another route :

>sh ip bgp 10.10.128.0/18
BGP routing table entry for 10.10.128.0/18, version 1109
Paths: (3 available, best #1, table Default-IP-Routing-Table, RIB-failure(17))
Not advertised to any peer
Local
10.0.5.1 from 10.0.5.1 (10.0.5.1)
Origin incomplete, metric 0, localpref 100, weight 32769, valid, internal, best
Local, (received-only)
10.0.5.1 from 10.0.5.1 (10.0.5.1)
Origin incomplete, metric 0, localpref 100, valid, internal
Local
10.0.0.1 from 0.0.0.0 (10.0.6.1)
Origin incomplete, metric 2586112, localpref 100, weight 32768, valid, sou rced

I want redistribute bgp one from 10.0.5.1 to eigrp but, metric much lower than current eigrp one. so, it is never selected if previous two existed.

I have tried, but not success. could anyone help me?

Any comments will be appreciated

Thanks in advance

Julxu

[Philip D'Ath]

The current EIGRP already came from BGP.  Can you show your config relating to the redistribution you are already doing?

[julxu]

redistribute bgp 64623 metric 10 5000 255 1 1500 route-map permit-default-to-eigrp

sh route-map permit-default-to-eigrp
route-map permit-default-to-eigrp, permit, sequence 10
Match clauses:
ip address prefix-lists: permit-default
Set clauses:
Policy routing matches: 0 packets, 0 bytes

sh ip prefix-list permit-default
ip prefix-list permit-default: 2 entries
seq 5 permit 0.0.0.0/0

[milan.kulik · Accepted solution]

Hi,

IMHO, you just need to add another line to the prefix-list:

ip prefix-list permit-default seq 10 permit 10.10.128.0/18

I'm a little confused by your sentence "I want redistribute bgp one from 10.0.5.1 to eigrp but, metric much lower than current eigrp one. so, it is never selected if previous two existed."

Did you mean "...metric much higher than current one..."?

In any case, I'd recalculate the metric used during the redistribution and compare with the original EIGRP one to be sure the redistributed prefix is really not winning within EIGRP.

Best regards,

Milan

[julxu]

Milan

yes, your right, the metric should be more higher, since it is backup link used.

But, to add another line for prefix-list is my original thought. and it was not work.

After I put this line in, rest routers was ok to stick active link, but the router which I have added this prefix-list will go to backup link. For some reason, it's metric more lower than active link.

Another thing comfuse me is the default route has no problem. On the configured router, it select correctly for active link. for some reason, the 10.10.128.0/18 select backup link.

That bring another question, which how can I find out the problem?

Regards

Julxu

[milan.kulik]

Hi,

are you saying the BGP route has changed on the router after you redistributed the 10.10.128.0/18 prefix to EIGRP?

Isn't there possible the EIGRP prefix 10.10.128.0/18 is redistributed back to BGP from some other router then?

How is the 10.10.128.0/18 route originated within BGP?

Best regards,

Milan

[julxu]

Ok, find the issue. Fixed now. Thanks for the advise.

[julxu]

Hi 

I thought it is working and test by cutted active link. and it went to backup link immediately.

But, it was staying in bakcup link not go back. On active link site, the absr router mentions the  backup link' route as external bgp and active link's route as internal bgp. so, bad luck to me, it select external first, and ignore itself's pass.

Do I have any chance to correct it? if so , how to? can I just increase the metrix to fix the internal/external issue?

Julxu

[milan.kulik]

Hi,

well, I'm not sure if I'm able to follow your design now.

Are you still talking about the same router or another one?

Generally:

To make BGP proces to choose the iBGP prefix instead of the eBGP one there should be enough to increase the Local Preference of the iBGP prefix.

But there might be another issue then:

If the same prefix would be received via EIGRP on the router, EIGRP prefix would win, as the iBGP AD is 200 by default (worse than EIGRP).

So you might need to play with ADs possibly, too?

Best regards,

Milan

[Philip D'Ath]

Your output in the original post says 10.10.128.0/18 comes "External protocol is BGP".  How is it getting from BGP into EIGRP?  The config you have posted does not show this.