iRule to modify the client IP to Virtual Server IP

Hi Meena,

 

 

You can create a SNAT pool containing the VIP address and then assign that SNAT pool to the VIP.

 

 

Aaron

I tried that and it is not working. Basically, I created a snat pool that contained the VS address. I modified VS by selecting the snat pool I created.

 

 

Will this require a loopback interface on the servers to get the routing correctly? The default gateway on the servers is set to be the router in this case and not the BigIP.

 

 

Do I need the default gateway to be the BigIP or do I need loopback on the servers or both?

 

 

Meena

If the destination host doesn't have an interface on the 10.2.2.0 (/24?) network it will use its routing table to respond to 10.2.2.2. That would probably mean it responds through its default gateway, the router. Does the router have a route back to the BIG-IP for 10.2.2.2? Changing the server's default gateway to the BIG-IP might work.

 

 

Why does the server need to get the request from the VIP address as the source IP?

 

 

Aaron

I am trying to load-balance print server connections between 2 windows print servers.

 

 

When we try to connect to the VS address, we get a network path not found error. However, I can use the ip address of eiher of the print servers (not the VS),I can view all the queues and print to them.

 

 

It is working with Cisco CSS. But I did client NAT on the CSS which changes the client's IP to VS. I also remembered that we added a loopback interface on the server for CSS to work.

 

 

I am trying the same way on the BigIP but it is not successful.

 

 

Meena

Are you trying to have the server respond back directly to the client? If so, it should work if without the SNAT. You'd want the server to get a connection from the BIG-IP with the client's IP as the source (no SNAT) and the destination IP being the VIP (destination address translation disabled). You'd define the VIP address on the server's loopback interface so that the server would reply back directly to the client using the VIP address. In the BIG-IP world, this is called nPath routing:

 

 

Configuring nPath Routing

 

https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm_sol_guide_943/sol_npath.html

 

 

I'm not sure why this would solve the issue you're seeing with network printing, but it sounds like what you did with the CSS.

 

 

Aaron

when you say "destination address translation diabled", do you mean uncheck the "address translation" and "port translation" on the VS?

 

 

Meena

sorry , I did not see the link. The document has all the info I needed.

 

 

Still troubleshooting the problem.

 

 

Meena

Finally, the problem is resolved.

 

 

I configured nPath routing on BigIP, configured a loopback interface on the server with the IP same as the VS and also had to set the DisableStrictNameChecking and the DisableLoopbackCheck options in the server's registery for the load balancing on the windows print server to work.

 

 

Thanks for your help Aaron.

 

 

Meena