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
num-packets 3
timeout 1000
frequency 3
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.
Question:
- 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!
