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Multiple ISP interfaces to one LAN interface

Hello,

   I am tasked with having to connect a whole new ISP to my already existing LAN during a change over. The sites are constantly feeding information and on a VRF (10.0.1.2 & 10.0.3.2) Which means, my old ISP pathway must remain online until all of the remote sites have switched over to the new ISP. Now, one ISP is in a closed off VRF (Site A to PE to CE). I need to have the new MPLS routed somehow to the same interface on my CE router (vice-versa) so that both MPLS connections are running at the same time and that from 10.10.100.2 they can reach both sites. I have attached a diagram, but I cannot figure out how to get both MPLS circuits to talk at the same time to 10.10.100.2. Is this as simple as IP route's? Am I missing something?

8 Replies 8

MHM Cisco World
Advisor
Advisor

same site both MPLS,
try divide the router to two VRF one for each MPLS,
second for LAN config it in global and config static route toward VRF-MPLS1 and VRF-MPLS2.
NOTE:- LAB this before apply in real.

I'm going to try this one out. Now, here's the other issue: how do I route certain traffic toward MPLS B from the 10.10.100.2 and not have it try and go towards MPLS A? Traffic cannot be dropped. Because it seems a static route only get it to interface GE 0/2.

mlund
Rising star
Rising star

Hi

If all 3 interfaces is configured for the same vrf, it is just routing.

/Mikael

CE-PE
now you have multi home i.e. two PE?
if yes and you use BGP between your edge router and SP router then using LP prefer OLD path.

paul driver
VIP Expert VIP Expert
VIP Expert

Hello


@michaelcarroll16725 wrote:

   I am tasked with having to connect a whole new ISP to my already existing LAN during a change over. The sites are constantly feeding information and on a VRF (10.0.1.2 & 10.0.3.2) Which means, my old ISP pathway must remain online until all of the remote sites have switched over to the new ISP. 

but I cannot figure out how to get both MPLS circuits to talk at the same time to 10.10.100.2


The current CE rtr has two EBGP peering towards two PE rtrs for subnets (10.0.1.0/30,10.0.3.0/30) which is clear, what isnt clear is then what you wish to do

Are you wanting to connect to a new isp/ on a new circuit from your CE rtr and keep the current routing path via the existing PE rtrs whilst the new ISP connection is soak tested?




Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

I need to route certain destination IP's toward MPLS B from the 10.10.100.2 and not have it try and go towards MPLS A? Traffic cannot be dropped. Because it seems a static route only gets it to interface GE 0/2. As I transition sites over the site that need to go towards MPLS A still work. We are slowly transitioning to a new ISP.

I mention before use LP

but

use route-map as following 
match ip prefix "prefix you want to pass through other MPLS"
set LP 

that it, it will effect only one prefix other will have it defualt value 100.

paul driver
VIP Expert VIP Expert
VIP Expert

Hello
I would say using weight on the specific received NLRIs would be the bgp attribute to use as it is not advertised to any other neighbor unlike local preference iand as you don’t have any ibgp peers it would be a preferred alternative and it is higher in the bgp best path selection process.

access-list 10 permit 10.0.3.0 0.0.0.3

route-map ISP2-Weight permit 10
match ip address 10
set weight 500000

route-map ISP2-Weight permit 99

router bgp xxxx
neighbor <isp2> x.x.x.x remote-as <ISP2>
neighbor <isp2> x.x.x.x route-map ISP2-Weight in


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul
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