10.2.4 LB::reselect doesn't seem to work

Does 10.234.133.222 $new_port actually exist in the pool?

I ask this because I think that LB:: commands typically are going to apply to the pool configured on the virtual server, or previously choosen with the "pool" command.

Yours is a truly odd requirement, but I think that the way to accomplish what you wish to accomplish is to make the selection earlier than LB_SELECTED (and not use LB::reselect), and then use the "node" command directly.

So for example, your irule look like:

`when CLIENT_ACCEPTED {
    get the relevant port number
    Call the node command to point to the IP address and server

}`

Possibly also since you seem to need the IP address of the server that the LTM will normally load balance to, instead of calling LB::reselect in your current irule, call LB::detach instead, and then call "node" to send the traffic to your desired server and IP address.

https://devcentral.f5.com/articles/irules-101-05-selecting-pools-pool-members-and-nodes

Yes. The IP exists in the pool, but the members are set to listen on any port.

There are two nodes in the pool and the load balancing method is observed(member) (Probably should be observed(node)), but that is why I'm trying to do this after the load balancing decision has been made. By defining what node to use at Client_Accepted I negate the load balancing. Essentially, if srvA is chosen I want to use the original destination port, but if srvB is selected the port must be incremented by one (it has something to do with the application design). We have attempted to use Client_Accepted, the rule was like this:

when CLIENT_ACCEPTED {

eval [LB::select]
if { [IP::addr [LB::server addr] equals 10.234.133.222] } {
set port [clientside {TCP::local_port}]
log local0.debug "Port = $port"
set new_port [expr {$port + 1}]
log local0.debug "New port is $new_port"
node 10.234.133.222 $new_port

} }

Using this rule, however, I never saw the log messages for this rule in /var/log/ltm and using a tcpdump, no traffic was ever forwarded from the backside interface when a connection was attempted to the VIP. It was as if the iRule stopped the traffic processing on that VIP all together. Perhaps the eval statement didn't have anything to evaluate and that is why log messages never appeared and no traffic was forwarded?

We will certainly try the LB::detach idea today. Thanks for the input. It is much appreciated. I will follow up with my results later.

can you try something like this?

 configuration

root@ve10(Active)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.24.9:any
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        tcp { }
    }
    rules {
        qux
    }
    snat automap
}
root@ve10(Active)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:any { }
        200.200.200.111:any { }
    }
}
root@ve10(Active)(tmos) list ltm rule qux
ltm rule qux {
    when CLIENT_ACCEPTED {
  set pick [LB::select]
  log local0. "pick=$pick"
  set ip [lindex [split $pick " "] 3]
  log local0. "ip=$ip"
  switch $ip {
    200.200.200.101 {
      node $ip [TCP::local_port]
    }
    200.200.200.111 {
      node $ip [expr {[TCP::local_port] + 1}]
    }
    default {
       do something
    }
  }
}
when SERVER_CONNECTED {
  log local0. "client=[IP::client_addr]:[TCP::client_port] \
    virtual=[clientside {IP::local_addr}]:[clientside {TCP::local_port}] \
    server=[IP::server_addr]:[TCP::server_port]"
}
}

 /var/log/ltm

[root@ve10:Active] config  tail -f /var/log/ltm
Oct 21 22:20:16 local/tmm info tmm[4955]: Rule qux : pick=pool foo member 200.200.200.111 0
Oct 21 22:20:16 local/tmm info tmm[4955]: Rule qux : ip=200.200.200.111
Oct 21 22:20:16 local/tmm info tmm[4955]: Rule qux : client=172.28.24.1:32828  virtual=172.28.24.9:80  server=200.200.200.111:81

Oct 21 22:20:38 local/tmm info tmm[4955]: Rule qux : pick=pool foo member 200.200.200.101 0
Oct 21 22:20:38 local/tmm info tmm[4955]: Rule qux : ip=200.200.200.101
Oct 21 22:20:38 local/tmm info tmm[4955]: Rule qux : client=172.28.24.1:32829  virtual=172.28.24.9:80  server=200.200.200.101:80

can you try something like this?

 configuration

root@ve10(Active)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.24.9:any
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        tcp { }
    }
    rules {
        qux
    }
    snat automap
}
root@ve10(Active)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:any { }
        200.200.200.111:any { }
    }
}
root@ve10(Active)(tmos) list ltm rule qux
ltm rule qux {
    when CLIENT_ACCEPTED {
  set pick [LB::select]
  log local0. "pick=$pick"
  set ip [lindex [split $pick " "] 3]
  log local0. "ip=$ip"
  switch $ip {
    200.200.200.101 {
      node $ip [TCP::local_port]
    }
    200.200.200.111 {
      node $ip [expr {[TCP::local_port] + 1}]
    }
    default {
       do something
    }
  }
}
when SERVER_CONNECTED {
  log local0. "client=[IP::client_addr]:[TCP::client_port] \
    virtual=[clientside {IP::local_addr}]:[clientside {TCP::local_port}] \
    server=[IP::server_addr]:[TCP::server_port]"
}
}

 /var/log/ltm

[root@ve10:Active] config  tail -f /var/log/ltm
Oct 21 22:20:16 local/tmm info tmm[4955]: Rule qux : pick=pool foo member 200.200.200.111 0
Oct 21 22:20:16 local/tmm info tmm[4955]: Rule qux : ip=200.200.200.111
Oct 21 22:20:16 local/tmm info tmm[4955]: Rule qux : client=172.28.24.1:32828  virtual=172.28.24.9:80  server=200.200.200.111:81

Oct 21 22:20:38 local/tmm info tmm[4955]: Rule qux : pick=pool foo member 200.200.200.101 0
Oct 21 22:20:38 local/tmm info tmm[4955]: Rule qux : ip=200.200.200.101
Oct 21 22:20:38 local/tmm info tmm[4955]: Rule qux : client=172.28.24.1:32829  virtual=172.28.24.9:80  server=200.200.200.101:80

Kudos to everyone here for these outstanding suggestions! Excellent work! Below is what I ultimately used to accomplish my goal.

when CLIENT_ACCEPTED {
    set pick [LB::select]  
    set ip [lindex [split $pick " "] 3]  
    switch $ip {  
      10.234.133.221 {
       node $ip [TCP::local_port]
       persist uie "[IP::local_addr]:[TCP::local_port]"
      }
      10.234.133.222 {
       node $ip [expr {[TCP::local_port] + 1}]
       persist uie "[IP::local_addr]:[TCP::local_port]" 
      }
      default {
        do something
      }
    }
}