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Cae_140395's avatar
Cae_140395
Icon for Nimbostratus rankNimbostratus
Aug 24, 2015

Apply conditional SNATPOOL

Hello all!

I am with a issue of SNAT.

My pool have pool-members from differents subnets. I need apply SNAT 10.100.2.253 when the choosen pool-members are from network 10.100.2.0/24 and the SNAT 172.26.160.71 to pool-members from network 10.100.6.64/27.

Are there a native configuration on BIG-IP 11.6. to solve this issue or do i need to apply an irule for this ?

I wrote two option of irules, but idon't know if is correct.

Data group with ip address from network 10.100.6.64/27:

ltm data-group internal DGROUP-THS {
    records {
        10.100.6.64/27 { }
    }
    type ip

SNATPOOL when poolmember 10.100.6.x are chosen:

ltm snatpool SNAT_THS {
    members {
        172.26.160.71
    }
}

SNATPOOL when poolmember 10.100.2.x are chosen:

ltm snatpool SNAT_DEFAULT {
    members {
        10.100.2.253
    }
}

1° Option irule:

when CLIENT_ACCEPTED {
if { [class match [IP::client_addr] equals DGROUP-THS]} {
snatpool SNAT_THS
} else {
forward
}
}
}

2° Option irule:

when LB_SELECTED {
if { [class match [LB::server addr] equals DGROUP-THS]} {
snatpool SNAT_THS
} else {
forward
}
}

And for two irule the snatpool SNAT_DEFAULT is set on virtual server.

application delivery
BIG-IP Access Policy Manager (APM)
deployment
devops
iRules
LTM
security
selective snat

1 Reply

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  • Kevin_Stewart's avatar
    Kevin_Stewart
    Icon for Employee rankEmployee
    Aug 25, 2015

    I don't really think you need two separate iRules:

    when CLIENT_ACCEPTED {
    if { [class match [IP::client_addr] equals DGROUP_THS] } {
        snatpool [class match -value [IP::client_addr] equals DGROUP_THS]
    } 
}

    where your datagroup includes two different entries:

    ltm data-group internal DGROUP-THS {
    records {
        10.100.6.64/27 { 
            data SNAT_THS
        }
        172.26.160.0.24 {
            data SNAT_DEFAULT
        }
    }
    type ip
}

    Or if you just have a default SNAT for anything that's not in the 10.100.6.64/27 subnet:

    when CLIENT_ACCEPTED {
    if { [IP::addr [IP:client_addr] equals 10.100.6.64/27] } {
        snatpool SNAT_THS
    } else {
        snatpool SNAT_DEFAULT
    }
}