Session Idle timeout regardless of the setting on LTM profile

Our network engineer has configured F5 to be used as a firewall, so all the communications between different VLANs are controlled via our F5.

 

Now, we are experiencing problems with the idle timeout between two different VLANs that get routed via the F5.

 

Our configuration looks like this:

 

 

ltm profile fastl4 /Common/np_dmz_storage_rules.app/pr-fastl4-dcfw-np_dmz_storage_rules-all-default {

 

app-service /Common/np_dmz_storage_rules.app/np_dmz_storage_rules

 

defaults-from /Common/fastL4

 

idle-timeout 3600

 

 

 

Even when the idle-timeout is set to 3600, one of the ends gets dropped after 300 seconds (which I believe it's the default)

 

 

I would appreciate any help you can provide on this issue. Right now, we're running out of options and we don't know where else to look out.

 

 

Some additional info:

 

- we're running version 11.2.0

 

- we tested the same communication between two servers that don't go through the F5 and it doesn't get dropped.

 

- netstat reports session is still active on one side after 5 minutes, on the other side it gets dropped.

 

 

Thanks in avance,

 

 

Sebastian