If you have a basic configuration on the ACE which consists of
VIP --> serverfarm -----> server1
-----> server 2
if one of the servers is removed or fails will the ACE detect this without probes being configured? and if so how does it detect the failure?
When you doesn't configure probe, ACE only detects server down with arp table.
It mean rserver goes down when arp timer is expired and rserver state will become ARP_FAILED.
Default arp timeout of rserver is 300 seconds as below.
ACE20/Admin# sh arp timeout
Learned Address : 14400 seconds
Configured Address : 300 seconds
Retry Rate : 10 seconds
Max retries per host : 3
Periodic Sync Interval : 5
You can change this value with 'arp interval' command on configuration mode.
However, this configuration change effects all configured address.
So, I recommend you configure probe.