Monitoring L2 channel. How to implement?

Question

network hardware

What we have:
The CISCO router is the main one, and the CISCO R1 router is remote.
There are two organized channels from the main router to the remote one. One channel is the main channel, the other is the backup channel.
On routers SUB interfaces are lifted.
The routers are configured with OSPF.

What is needed: It is
necessary to organize monitoring of the performance of channels.

What is the problem:
For example, the ip address of the backup channel is set for monitoring, which is located on the gi0 / 0.100 subinterface of the R1 router. And in theory, in case of any channel malfunctions, ping to this address should disappear. BUT it turns out that this ip address on gi0/0.100 of router R1 starts pinging through the main channel. And we can not assess the real picture of what is happening. A similar situation with the main channel, in case of a channel failure, the channel address on the subinterface starts pinging through the reserve.

Question:
How can monitoring of each of the channels be organized in order to see the real picture of what is happening.

Answer 1

three options at once:
1. monitor the state of the ospf neighborhood (1.3.6.1.2.1.14.10.1.6) plus pings
2. switch to BGP and filter link addresses
3. encapsulate in GRE MPLS VXLAN whatever