SNAT and Next hop based on Node address

Hello,
Correct this iRule and test this one and let me know :

when LB_SELECTED {
# Once pool member has been selected check if it's 1.0.0.2
if { [IP::addr [LB::server addr] equals 1.0.0.2] } {
snat automap
}  }
In this iRule, when a pool member is selected, it checks if the server's IP address (`[LB::server addr]`) is equal to `1.0.0.2`. If the condition is true, it applies the `snat automap` command, enabling automatic SNAT.

make sure you are assigning specific route for such routed flow for this node. and note that the iRule assumes the IP address `1.0.0.2` is the specific condition you want to match. Make sure to adjust it according to your specific requirement and don't enable snat under such VIP but only this iRule.

Best,
MSaeed

vbhugra Any particular reason you can't always have a static route for the single host that is behind the router? In addition to that I do not recommend using snat automap and instead I would use a snatpool and then use the IP of the virtual server in question in that snatpool and name that snatpool as SNAT-<VS_IP>. The other thing I would do is create 2 pools, one for the device directly connected to the F5 and then the other with the device that is behind the router. After you have done that you should be able to use the following iRule to accomplish what you would like. Make sure the pool that has the pool member that is directly connected to the F5 is associated as the default pool for the Virtual Server in question.

when CLIENT_ACCEPTED priority 500 {

    set DEFAULT_POOL [LB::server pool]

}

when HTTP_REQUEST priority 500 {

    if { [active_members [LB::server pool]] == 0} {
        snatpool SNAT-<VS_IP>
        pool POOL-ServerBehindRouter
    } else {
        pool ${DEFAULT_POOL}
    }

}

Hi vbhugra,

Please try follow step below,

1. You have to create pool with priority group less than 1 and prefer prioruty on direct node more than other node

2. Create irule below and apply to virtual server

when CLIENT_ACCEPTED {
if { [active_members your-pool] > 2 } {
snat automap
}
}

or

when LB_SELECTED {
if { [IP::addr [LB::server addr] equals 10.222.45.252] } {

snat automap
}
}

https://clouddocs.f5.com/api/irules/LB__server.html

I hope this information will help you

Thanks everyone I figured the solution 

when CLIENT_ACCEPTED priority 500 {

set DEFAULT_POOL [LB::server pool]

}

when LB_FAILED priority 500 {

if { [active_members [LB::server pool]] == 0} {
LB::reselect snatpool SNAT_REP
LB::reselect pool DBS5G_REP_REMOTE
LB::reselect nexthop /DBS/DBS_CLIENT_174 10.219.30.65
} else {
pool DBS5G_REP_LOCAL
}

}