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AnuragMishra_13's avatar
AnuragMishra_13
Icon for Nimbostratus rankNimbostratus
Feb 19, 2014

Source NAT

I have a virtual server with 2 real servers. As I am enabling SNAT I see the connections are not successful. Without SNAT it works well. I have chosen VIP as NAt IP. In pool setting Allow NAT is checked.

 

I have checked routing. Is there anything I am missing here?

 

application delivery
availability
deployment
LTM

1 Reply

  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Feb 19, 2014

    Both "Allow NAT" and "Allow SNAT" should be enabled/checked in the pool config. What do you mean by "I have chosen VIP as NAt IP"? A SNAT should use an address, a self-IP address if using automap, that is in the same subnet as the real server (or at least an address that the real server can route back to). With SNAT automap enabled, run a TCPDUMP capture:

    tcpdump -lnni 0.0 [additional filters]

    where [additional filters] is anything you may need to focus in on specific traffic (ex. port 80 and host x.x.x.x and host x.x.x.x). What you want to see is client traffic arriving at the VIP - source address is the client's IP and destination in the VIP's IP. Then (again with SNAT automap applied) traffic arriving at the server - source address is the internal self-IP of the F5 and destination is the server's IP. With that you should see response traffic flow back the same direction it came.