Bigip LTM3900 - worng interface source IP address for traffic sent to pool nodes

Hi all,

 

hope you can help me on a strange issue we have on our load balancer (LTM3900).

 

Basically we found that every new VIP/pool we create doesn't work as when the Bigip make the request to the real nodes it gets the IP address of another interface as source and then there is no traffic back from the nodes.

 

Example Port 1.1 - internal - IP address 10.1.1.1 Port 1.2 - servers - IP address 20.1.1.1

 

when traffic is made to the VIP balancing servers, a TCP dumo report traffic going out the correct interface 1.2 but with source address 10.1.1.1 instead of 20.1.1.1 and, obviously, it doesn't work.

 

this is very strange as there are other previous existing VIPs/Pool already configured for other servers and there is no issue at all, for these traffic shows the correct IP 20.1.1.1 as source but no luck with any new addition one.

 

We tried everything, creating several other new VIPs/Pools, reloading the Bigip, but traffic has the IP address of the other interface as source everytime.

 

Did you have a similar issues and able to help please?

 

Thank you