ISP Load Balancing, SNAT pool instead of Automap link self-ip, anyway to do health check ?

Hi,

Configured F5 as ISP Load balancing, created vs 0.0.0.0, working fine with Automap. We have 3 x DIA from different ISP, each has /27 IP assigned, configured default_gateway_pool with health monitor on the uplink router IP. When one of the DIA down, traffics would be NATed using other 2 links self-ip.

As each DIA has /27 subnet mask, we would like to use other public IP on the DIA instead of the self-ip as source IP. SNAT pool works fine but when one of the links down, we have got intermittent internet access problem. It seems that F5 could pick the SNAP IP from the pool which connects to shutdown DIA.

Is there anyway to configure the SNAP pool IP selection based on the status of the default_gateway_pool heath check status ?

Thanks in advanced.