10-12-2010 08:36 AM - edited 03-04-2019 10:05 AM
Any help with this would be appreciated.
For the purposes of this question I have two sites, each site has an OC3 to an MPLS cloud. Each MPLS router is running BGP and EIGRP. I'm redistributing EIGRP into BGP and BGP into EIGRP. Also at each site is a Frmae Relay backup network off of the LAN, which is running the same EIGRP AS as the MPLS router. I want all of the traffic to take the MPLS network, however since the MPLS routes are being redistributed into EIGRP they are external EIGRP routes, while the frame relay routes are internal EIGRP so all of the traffic is traversing the frame network rather than MPLS.
What is the best way to get the redistributed BGP routes to be preferred over the EIGRP routes? I've see different ways to do this and have gotten conflicting information.
raise the AD of the interal eigrp routes
router eigrp 20
distance <value> < source address > <wild card mask> <access-list>
Set a weight when redistribuing BGP into EIGRP
router eigrp 20
redistribute bgp 2000 metric 45000 10 255 1 1500 route-map BGP->EIGRP
network 10.0.0.0
no auto-summary
!
router bgp 2000
no synchronization
bgp log-neighbor-changes
network 0.0.0.0
redistribute connected
redistribute eigrp 20
neighbor 1.1.1.1 remote-as 65000
neighbor 2.2.2.2 remote-as 65000
no auto-summary
!
access-list 20 permit any
!
route-map BGP->EIGRP permit 10
match ip address 20
set weight xxxx
set local-preference xxxx
10-12-2010 09:08 AM
I can't read .vsd files so this may not be relevant. Perhaps you could post as a .jpg.
Anyway, if your 2 WAN routers (MPLS/frame-relay) connect back to a core pair of switches easiest way is to have the MPLS router redistributing full routes into EIGRP and have your frame-relay only dsitributing a default-route. The core switches will then see a default via frame but will only use that if the full routes are not being received.
If you are also redistributing a default-route from the MPLS router you could use a floating static on the core switches pointing to the frame-relay router and then simply not distribute an EIGRP learned routes from the frame router to the core switches.
Jon
10-12-2010 09:45 AM
10-12-2010 10:22 AM
So is the BGP router distributing a default-route into EIGRP ?
Jon
10-12-2010 10:26 AM
Yes, for failover in case the local Internet goes down.
10-12-2010 10:37 AM
Can you just clarify from your diagram.
The BGP MPLS router redistributes into EIGRP
The frame router exchanges EIGRP internal with the other end and so is preferred
The internet connected router showing IPSEC GRE tunnel - is this also exchanging EIGRP routes ? And what is the order you want to use the links ie.
BGP
Frame
IPSEC/GRE ??
Jon
10-12-2010 11:30 AM
The BGP MPLS router redistributes into EIGRP
The frame router exchanges EIGRP internal with the other end and so is preferred
Correct.
The internet connected router showing IPSEC GRE tunnel - is this also exchanging EIGRP routes ? And what is the order you want to use the links ie.
BGP
Frame
IPSEC/GRE ??
The MPLS circuit is new and will be replacing the IPsec/GRE tunnel between the sites. So that can be ignored, I should have taken it out of the diagram. So I am looking for all traffic to go over the MPLS circuit and fail over to the frame circuit.
10-12-2010 12:08 PM
Thanks for the clarification.
Okay personally i think there are 2 options -
1) it's not clear which routers will be disappear from the topoplogy when you get rid of the IPSEC/GRE but it looks like the main router connecting to the internet router will stay as it has at least one other router connecting to it. So using a floating static would mean adding it to 2 routers ie. the one on the right of the frame router and the one below. You would then need to stop the frame router from sending any EIGRP routes to these routers.
But messy, especially considering the routers hanging off the bottom router may also be receiving EIGRP routes.
2) Change the AD of internal EIGRP as you suggested and then in all probability you would need to use an offset-list on the frame router to make sure that the routes redistrinuted from BGP are preferred within the site.
Jon
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