NAT working intermittently?

Do you have a NAT defined for a host that's also a member of a pool? If so, and the issue is indeed with the BIG-IP, I'd take a wild stab in the dark and say the issue might be a conflict between the NAT and load balancing.

 

 

A simple way to test this would be to remove the NAT and replace it with a VIP. The VIP would be defined with your old NAT address and have a single member in the pool (the node you want to connect to). You could either create a single port or all port VIP depending on your requirements. For outbound access from the node(s) to the internet, you could create a default SNAT enabled on the VLAN(s) you want source translation performed for, or another wildcard VIP.

 

 

You can check SOL2251 (Click here) for a few different options for gaining admin access to nodes.

 

 

Aaron