Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

sandiksk_35282's avatar
sandiksk_35282
Icon for Altostratus rankAltostratus
8 years ago

irule to force traffic to a particular server.

I need some help as we are forcing some reverse proxy server traffic ( acting as source ) to go a specific pool member   Reverse Proxy Server 1 ------------------> Pool Member 1 Reverse Proxy Ser...
application delivery
irules
LTM
Simon_Blakely's avatar
Simon_Blakely
Icon for Employee rankEmployee
8 years ago
when CLIENT_ACCEPTED { 
  if { [IP::client_addr] == "10.20.1.111" } 
    { pool prod_443 member 10.9.41.25 } 
  elseif { [IP::client_addr] == "10.20.1.142" }
    { pool prod_443 member 10.19.41.24 } 
}

Your irule selects specific pool members for each client IP.

There is no provision for a load-balancing decision if the selected member is unavailable.

You need to check the status of the pool member with LB::status

Something like the following, although I have not tested this ... 
when CLIENT_ACCEPTED { 
   get the default load-balancing pick
  set mypick [LB::select]
  if { (([IP::client_addr] == "10.20.1.111") && ([LB::status pool prod_443 member 10.9.41.25 443] eq "up"))  } 
    { pool prod_443 member 10.9.41.25 } 
  elseif { (([IP::client_addr] == "10.20.1.142") && ([LB::status pool prod_443 member 10.9.41.24 443] eq "up"))  }
    { pool prod_443 member 10.19.41.24 }
   the default pick is chosen 
  else { eval $mypick }
}