Thanks Denny, this is a very timely post for me.
Extending this scenario a little, I also have virtual servers defined on VLAN X and Y, which use pools of servers in VLAN A and VLAN B respectively. Client requests come in from beyond VLAN X or Y.
Where will the reply traffic be forwarded to? I imagine the forwarding virtuals you mention would only be relevent for sessions initiated on the server side (VLAN A/B), not for return traffic for sessions initiated beyond VLAN X & Y.
To extend your diagram per below, suppose 10.11.11.100 sends traffic to virtual 10.10.10.10. How will the BigIP know to send return traffic back to 10.10.10.254? I'm sure we could set up the route tables such that 10.11.11.x is via 10.10.10.254 and 192.168.3.x is via 192.168.2.254, but what if we don't have a full knowledge of the remote network addressing?
Also, if we are trying to segregate different customers, they may have addresses which overlap each other.
---------------- ------------------
- 10.11.11.x - - 192.168.3.x -
---------------- ------------------
| |
ROUTER ROUTER
| |
---------------- ------------------
- 10.10.10.254 - - 192.168.2.254 -
---------------- ------------------
| |
VLAN X VLAN Y
| |
| |
---------------------------------------------------
- 10.10.10.x 192.168.2.x -
- F5 LTM -
- 172.18.10.x 172.18.12.x -
- -
---------------------------------------------------
| |
VLAN A VLAN B
| |
server server
Thanks,
Stephen