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

Same host but different IP addresses on the host example

 

 

10.10.10.1 NAT to 10.10.11.1

 

10.10.11.2 on same host and in pool but the 10.10.11.1 address is not in a pool.

 

Hrmm... that was my best guess. Maybe someone else has ideas?

 

 

Else, it might be worth trying to replace the NAT with a VIP.

 

 

Aaron

Thanks for the reponse and I might have to go with the VIP replacement for NAT but for now I am just trying to make sure that there was not some known issue out there with NATs being set up correctly and behaving badly. But I do appreciate whenever anyone responds in these forums as it is always helpful.

Could be an idle timeout issue if his application is idle for a while and doesn't know how to reestablish the session if it's cut off. Default idle timeout on NAT's is probably 300 seconds (I'm not next to a box at the moment to check that).

 

 

Denny

How do I check the timeout for the NAT?