I have a VIP, which is listening on port 8312 in ACE LB and NO probes attached to it. In this scenario how does the ACE module perform the health monitoring? Any input is appreciated.
The ACE will monitor TCP connection messages to determine successful or failed connections to your rservers. By default, it won't take any action but you can configure it to do so.
More information here:
Thank you for the quick response.
One more question - if no probes are atatched and in-band monitoring is NOT ocnfiured then does the ACE module perform any monitoring and mark the server down if the real server is down. if so, how does it indentify the status of the backend server? ARP? or ICMP?
Not clear if you have in-band monitoring configured.
But anyway, if rservers are directly attached to ACE (in the same L2 domain), ACE tries to resolve ARP for those rservers and if fails - it put them into non-operational state.
Any other health monitoring has to be explicitly configured. If rservers are not in the same L2 domain with ACE - ARP monitroing doesn't work.
That explains the behavior. In-band monitoring is not configured. The rservers are not in the smae L2 domain. They are on a different VLAN, which is not directly configured in the ACE. We use source NAT to load balance these rservers.