this command has to be given in interface configuration mode here is the beauty of the whole thing
Enter configuration commands, one per line. End with CNTL/Z.
router(config-if)#ip summary-address eigrp 100 172.16.0.0 255.255.0.0 ?
<1-255> Administrative distance
So you can have control of what routes are sent on backup point-to-point links
Until a most specific route is received over the MPLS Link it should be used even if it is a D EX because the most specific route is used first and then if two prefixes with same len exist it compares AD and metric
Hope to help
I need every network on every link. Except, I need the MPLS to be the primary.
So Do I need to do 'ip summary-address...' for every single network i want to advertise?
I'm not completely understanding how this is going to work.
So if I do this on the 4507, will the 2851 know those networks are attached to it via EIGRP.
the feasibilty of what I'm suggesting depends from your current address plan:
a hierarchical address plan allows for summarization: a summary route still allows you to reach remote sites' ip subnets but with less details.
You can summarize if this doesn't create ambiguity:
172.25.15.0/24 are both associated to site M
from the other side point of view
routing to both happens in the same way
so a summary route of 172.25.14.0/23 that will take both in a single entry still allows to reach hosts in 172.25.14.0/24 and in 172.25.15.0/24 but with less detail.
If you can put your routers in the same scenario the detailed routes via MPLS Links will be preferred and used until they are alive.
172.25.14.0/24 belongs to site M
172.25.15.0/24 belongs to site N
if you create an aggregate 172.25.14.0/23 you can create problems.
If your address plan doesn't allow for some summarization other solutions are needed.
You may even think to use a second EIGRP process on backup links and have it redistributed into the main EIGRP process.
But I think you should be able to perform some summarization: the requirement is not to create a single prefix that will represent site M but few less specific routes.
Hope to help
I'm still not clear on how this is going to help me out. I'm not sure how this will get the 2851 to look to the 4507 for routes.
the 2851 should look to the 4507 for EIGRP routes.
The 3660 looks at the 4507 for EIGRP routes. But the 3660 is also connected to Lexington which is giving me the looping problem.
So how do I fix the AD problem so the 2851 looks to the 4507 for the EIGRP routes instead of looking at the loop?
if I understand correctly your scenario:
2851 ----- MPLS ------- 2821---
4507 ----| |---4507
3660------ p-t-p ------ 3640---
EIGRP <> BGP <> EIGRP
EIGRP ------------------------------ EIGRP
where <> means redistribution
on the remote 2821 you need to filter the EIGRP routes so that into BGP only the local site routes are redistributed
You need to add a route-map with a prefix-list and only prefixes matching the prefix-list are to be reditributed
the loop is formed by the point-to-point link providing in the EIGRP of the remote site the same prefixes of the local site.
router bgp your.AS
redistribution eigrp your.EIGRP:AS route-map filter-routes
match ip address prefix-list loca-routes
you need to filter everywhere
What I was suggesting is also beneficial because if out the point to point less specific routes are injected they cannot compete with local routes in doing the whole tour: it is the point-to-point link that provides a leakage path for local sites routes but if they are sent out less specific they again cannot compete with the legitimate routes coming over the MPLS link.
Probably this was suggested already by Jon the filtering based on site routes.
I would implement both methods to provide a complete control.
Hope to help
ok i understand what you are saying about filtering from the routes.
Attached is the network topology.
i hate asking for handouts but can you tell me if this is the correct commands I should be putting in my 2821
how do i create a pre-fix list? Which pre-fixes should I be putting in this list? The local only prefixes?
router bgp 64803
redistribution eigrp 101 route-map Filter-Routes
what do i need to remove from the current configuration? jpg attached with config
follow Jon's instructions in his today's posts you need first of all to fix the wrong redistribution of EIGRP into BGP that is creating the misbehaviour.
Then later, you can work on the way to make the backup links really backup.
Hope to help