VIP Bounce - I am facing a Show stopper

Thanks Kevin for your prompt replies.

1) verify your etherchannel configuration

I have created trunk (1.1 and 1.2) and allowed vlan on it this VLAN is same as the serverfarm and VIP . I havent configured LACP on it. On the cisco switch side , i have configured etherchannel and mode has been configured as desirable. Is it a wrong config ? do i have to add anything further?

2) make sure you can ping these servers from the F5 and that ARP addresses are correctly resolved,

I am able to ping the all the servers from the load balancer . However , initially i was not able to ping the default gateway and it was not showing the arp as well. When i statically added the mac-address of the Core switch , i was able to reach the gateway. I thought that this would be some kinda arp issue. but couldnt relate it to any etherchannel related issue as "only" the gateway |from the F5 box"wasnt reachable but from anywhere in the lan ( other subnets as well) i was able to ping the VIP. (172.16.4.45)

3) observe your /var/log/ltm log data for any possible anomalies

Couldnt actually observer any other than abnormal other than a real server issue which was genuine and has been taken out from the pool.

Any clues , where should actually peek in to , since i have no clue , how should i address this tomorrow :-(

-Paddy