HELP! Route in iRules to fix assync routing

 

I am a newbie with iRules and I don't know how to fix this issue. Here is what we have:

 

1) A pair of BigIP V4.5.10 (X1, X2) that is on the public internet and handles traffic for smtp, http and others. Let's call it "X-Pair".

 

2) A pair of BigIP V9.3.1 (Y1, Y2) that is also on the public internet and handles traffic for smtp, http and others. Let's call it "Y-Pair".

 

3) Depending on the protocol the traffic will always hit BigIP X-Pair and it will be sent to BigIP Y-Pair. We implement this by making some VIPs on BigIPs Y-Pair as a pool member of BigIP X-Pair. Here is a problem example: The http traffic comes in a VIP on bigIP X-Pair, then the traffic is sent to the pool member, which is the VIP in the BigIP Y-Pair, then since BigIP Y-Pair can talk directly to the source IP (public internet), it will send the traffic back directly to the public internet address, not via the same route (through BigIP X-Pair) that it came from.

 

 

Is there a way to create an iRules on BigIP Y-Pair (V9) that forces a route back to BigIP X-Pair (V4) depending on the VIP it is hitting on BigIP Y-Pair when the traffic is coming from X-Pair?

 

 

I hope I could make the question clear.

 

 

NOTE: We already tried a few things on BigIP X-Pair, such as SNAT and no luck so far.

 

 

Thanks,

 

 

Sandro