Hello. This is my first post to the Cisco Community. Please be gentle if I make any mistakes. I'm in dire straits and really hoping you all could be so kind as to share some of your knowledge with me.
I recently started working for a municipal entity which runs a 100+ site microwave MPLS network used primarily for backhaul of their public safety radio communications, site environmental alarms and other agencies data.
The hub sites (sites that go in more than 2 directions) are ASR 1002s while all other sites have 3560X switches. I inherited this network and was told switches were used in place of routers since most sites were remote and to save money.
Every ASR has a Mgmt VRF on it, interfaces facing a switch have a .50 subinterface with a /29 subnet and every switch has a VLAN 50. There is also a .100 subinterface advertised via OSPF for the iBGP mesh.
Where I'm having issues is this:
R1-- SW1 -X- SW2 -- R2
Where the "X" would be a break in the microwave path. In this example, R1's .50 and SW1 would be able to talk to my NMS server, but R2's .50 and SW2 would not. I *think* this is because the switches are L2 and there's nothing to tell the subinterface the current valid/best path is bad. This wouldn't be an issue with a CE router since they'd be peered with both ASRs. This VRF is only for management of the routers and switches.
The command "sh ip bgp vpnv4 vrf Mgmt" shows R1 as the valid/best route to reach the segment /29, but it doesn't seem to know there was a break in the path to R2.
I'm guessing there needs to be some form of routing performed on the switches. The switches will need to take either R1 or R2 to get back to the NMS server.
Do I need a new OSPF instance for the Mgmt vrf on each ASR and 3560s? Static routing would be difficult I think since I'd have to set up an IP SLA ICMP echo on each switch (there's over 100) pointing to both ASRs. Please tell me there's a more elegant solution and I just have tunnel vision. Thank you all for taking the time to read this and respond.
Here is an example of one of our network segments I made up in the lab.
What happens is a failure occurs on the microwave hop between SW1 and SW2 and one of the switches loses connectivity to the NMS depending on which route was valid/best at the time.
