Configuration Help Big-IP LTM VE

Two things have to happen:

 

1) your clients on the 192.168.0.x subnet have to know how to reach the virtual server that you've created. Something simple to try would be to address the virtual server with a 192.168.0.x IP, then no routing issues are happening for that portion of the connection.

 

 

2) Your web servers aren't routing through the LTM. This is OK for most protocols - simply enable a SNAT and all inbound client requests to the virtual that you've made will show up to your web servers with a SNAT'd IP address that's been configured on the 172.16.12.x subnet.

 

 

I suggest digging around for information on SNAT.

 

 

This is what a connection might look like, given these definitions:

 

- A virtual server configured with the address of 192.168.0.10.

 

- the virtual server has a pool of nodes for resources.

 

- one of those nodes is 172.16.12.11

 

- the virtual server is set to SNAT automap

 

 

- the BIG-IP LTM VE has the self IP address 172.16.12.5

 

 

- the client is addressed as 192.168.0.201

 

 

 

The client wants to make a request like this:

 

source: 192.168.0.201, destination 192.168.0.10 (on TCP port 80 for HTTP, for example)

 

 

the client will look at it's routing table, and determine that it knows how to locally reach the 192.168.0.x subnet. As such, it will ARP for the 192.168.0.10 address.

 

 

The BIG-IP LTM VE will respond to this ARP request and the client accepts it.

 

 

The client then sends traffic for 192.168.0.10 to the BIG-IP LTM VE.

 

 

The original request operation is now a packet, and the packet looks like this:

 

source: 192.168.0.201, destination 192.168.0.10 (on TCP port 80 for HTTP, for example)

 

 

The packet reaches the BIG-IP LTM VE. The LTM does it's "magic" and figures out that it needs to send the packet to 172.16.12.11 for processing.

 

It will put this packet on the wire:

 

source: 172.16.12.5 destination: 172.16.12.11

 

 

the return packet from the server will look like this, which will be directed back to the LTM (and not go through the gateway 172.16.12.1 !):

 

source: 172.16.12.11 destination: 172.16.12.5

 

 

The BIG-IP LTM VE processes the packet and returns the response to the client. The response packet will look like this:

 

source: 192.168.0.10 destination: 192.168.0.201