I have two connections to one ISP (one is over Radio channel the other is on-ground) who provides me with pool of public IP addresses. On my border routers (3825) I have BGP which announces this pool of addresses via one or another router (depending which channel is available. On-ground has higher priority.) On ASA I configured SLA:
route outside 0.0.0.0 0.0.0.0 x.x.x.3 1 track 1
route outside 0.0.0.0 0.0.0.0 x.x.x.4 250
sla monitor 10
type echo protocol ipIcmpEcho [on-ground default-gateway] interface outside
sla monitor schedule 10 life forever start-time now
I have tested the SLA by shutting down the primary (on-ground) Internet channel. Everything worked fine: the default gateway switched to the Radio channel and back when I turned the on-ground channel back on.
The problem is: After some time (5 - 10 hours) ASA looses the default gateway and all services behind ASA become unavailable. After I reaply the SLA configuration provided above everything work fine for the next 5 - 10 hours and then it looses the default-gateway again.
- Does SLA on ASA work correct if the next hop for both DG are in one subnet. Technically there should be no problem but In all examples I have seen, never have I met that situation (next hops were always on different subnets)?
- If not first. What could be the problem?
- Are there any better ways to provide switching between two Internet channels in my situation?
Any help is appreciated!
Should not be any problem, but you can track an IP avaiable to that path (instead of tracking the default gateway).
For instance, let's say you create a route:
route outside 220.127.116.11 255.255.255.255 gateway1
You can track 18.104.22.168 via interface outside (since that specific IP is always going to be reachable via that interface).
Let me know if the problem persists.