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Luis_Araujo_560's avatar
Luis_Araujo_560
Icon for Nimbostratus rankNimbostratus
Dec 18, 2017

Snat Pool Member Persist

Hello @ALL,

 

I´m facing issue with a snat persist. I need to persist a outbound connection in same snat pool member.

 

How is my scenario:

 

Clients -> Web Proxy -> F5 LTM -> ISP "X.X.X.X/28"

 

How is my virtual server config:

 

  • VS Forwarding ALL (0.0.0.0/0) - Forwarding IP;
  • Source: Proxy IP (10.20.30.40/32);
  • All Protocols;
  • Snat Pool: snat_pool_isp (200.1.2.1, 200.1.2.2, 200.1.2.3);
  • Pool: pool_default_gw (isp_member: 200.1.2.254).

Well, When the proxy forwarding the client's connection with the internet, I need to select a IP (member) of snat pool and persist that connection in the same snat pool member.

 

I mean, if a client starts a connection with the internet, he should always uses the same IP that was selected in snat pool

 

I tried to do some iRules, but I had not success.

 

Can someone help me about that?

 

Kinds Regards. Luis Araujo

 

application delivery
iRules
LTM
  • Patrik_Jonsson's avatar
    Patrik_Jonsson
    Icon for MVP rankMVP
    Dec 19, 2017

    Fun exercise! Not sure if I nailed the server side event here since it's a forwarding server. You might want to play around a bit with that part, but other than that this could work.

    when CLIENT_ACCEPTED {

    set newrecord 0

    if { [table lookup "ippersist[IP::remote_addr]"] == "" } {
        snatpool myPool
        set cip [IP::remote_addr]
        set newrecord 1
    } else {
        snatpool myPool member [table lookup "ippersist[IP::remote_addr]"]
    }

}

when SERVER_CONNECTED {

    if { $newrecord == 1 }{
        table set "ippersist$cip" [IP::local_addr] indef indef
    }

}