IP SLA for dual MPLS failover

[WilliamHengSGP]

Currently I have 2 MPLS of the same provider, MPLS A 40M and MPLS B 20M. I have a few VLAN for different purpose, VLAN 10, 20, 30, 40, 50 for infrastructure(and normal users) and VLAN 60 for VIP users.

My intention here is to use the 40M for infrastructure VLANS and 20M for VLAN 60 which is VIP access. So VLAN 10 to 50 will use MPLS A and VIP users will all be on MPLS B. So when MPLS A fail, all VLANs will pass via MPLS B and vice versa for MPLS B failover to MPLS A.

Currently, i have all VLANs advertised on both MPLS.

1. Is there any way i could use IP SLA to help me in failover at core switch level?

2. If i could use IP SLA to failover at MPLS end which instead of advertising all VLANS in both MPLS, i will advertise required VLAN at each MPLS and IP SLA to advertise the rest of the segments when i failover.

Please help me out here.

[Francesco Molino]

Hi

In order to give you the right answer and/or a method to achieve what you want, can you give me more details on how you're advertising your subnets on the mpls?

[WilliamHengSGP]

I don't have visibility on ISP router, as far as i know, individual /24 is advertised out to the MPLS probably via static redistribution. There is no dynamic routing in place between core switch and MPLS router too.

[paul driver]

Hello

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@WilliamHengSGP wrote:

I don't have visibility on ISP router, as far as i know, individual /24 is advertised out to the MPLS probably via static redistribution. There is no dynamic routing in place between core switch and MPLS router too.

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If you dont have no control on whats being advertise into your ISP PE edge rtrs  then its seem you may need to liaise with your ISP as to what you want then to advertise on your behalf .

res
Paul

[Francesco Molino]

Ok then I understand that you have static routes on your side and not doing any dynamic routing with your MPLS SP. If so, you can have some static routes with IP SLA to forward the traffic on the right link as outbound but how the SP is managing the inbound today? To mirror what your doing for outbound on inbound, you'll need to work in collaboration with your SP.

[WilliamHengSGP]

I do understand but seems like SP is not sending the right person to help us on this so i have to seek help here. I am also hoping to understand more on IP SLA, like can i actually trigger a set of commands for the interface if the IP SLA lose track of the reachability.

[Francesco Molino · Accepted solution]

Ok here to forward the traffic based on the source vlan, the routing is called PBR. You can add SLA to track something like an IP or interface and if this track goes down then forward the traffic using the normal routing table information.
Here a good documentation mixing both and giving your some explanation:
https://networklessons.com/cisco/ccnp-route/reliable-pbr-with-ip-sla/

However, if you don't have any firewalls, there won't be any issues. The traffic could be asymmetric as it will come inbound from any of your ISPs.