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vbhugra's avatar
vbhugra
Icon for Nimbostratus rankNimbostratus
Nov 10, 2023

SNAT and Next hop based on Node address

I have a requirement wherein I have 2-nodes in a pool; of which 1 node is directly connected to F5 and the other one is behind a layer-3 router. I want to make an iRule if the directly connected nod...
devops
T-Trust's avatar
T-Trust
Icon for Cirrostratus rankCirrostratus
Nov 13, 2023

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

 

  • vbhugra's avatar
    vbhugra
    Icon for Nimbostratus rankNimbostratus
    Nov 13, 2023

    Hello, 

    I tried what you mentioned but did not work. The thing I observed is my first condition is not working, the second one always works. So I assigned the priority 10.219.45.114 - 30 and 10.222.45.252 - 20.  The Irule does not work. Whereas I changed the priority and moved 10.222.45.252 - 40, it works.

    when LB_SELECTED {
    if { [IP::addr [LB::server addr] equals 10.219.45.114] } {
    node 10.219.45.114
    } else {
    LB::reselect snat automap
    LB::reselect nexthop /DBS/DBS_CLIENT_174 10.219.30.65
    }
    }