irule to load balance to specific ISP based on source IP

Create 2 pools :

• Pool_GW_ISP1

   

  • priority group activation : less than 1
  • ISP1_GW:0 priority 10
  • ISP2_GW:0 priority 1

• Pool_GW_ISP2

   

  • priority group activation : less than 1
  • ISP2_GW:0 priority 10
  • ISP1_GW:0 priority 1

create 2 VS

• VS_FWD_OUT_SUBNET1

   

  • source : SUBNET1 (ex : 10.1.0.0/16)
  • destination : 0.0.0.0/0
  • service : any
  • translate address : disable
  • pool Pool_GW_ISP1
  • source address translation : automap

• VS_FWD_OUT_SUBNET2

   

  • source : SUBNET2 (ex : 10.2.0.0/16)
  • destination : 0.0.0.0/0
  • service : any
  • translate address : disable
  • pool Pool_GW_ISP2
  • source address translation : automap

First create a ISP pool. Based on source IP and port you can send traffic to specific pool.

when CLIENT_ACCEPTED { if {[IP::addr [IP::client_addr] equals 10.x.x.x] or [IP::addr [IP::client_addr] equals 192.x.x.x]} { if { [TCP::local_port] == 443 } { pool ISP-POOL } else { reject } } else { reject } }

Hi Hawary,

you may use the iRule below on your

IP-Forwarding

• If ISP1 is available it will route traffic from Network 1 to ISP1
• If ISP1 is available it will route traffic from Network 2 to ISP2
• If ISP1 is offline it will route traffic from Network 1 to ISP2
• If ISP1 is offline it will reject traffic from Network 2

Note: You don't have to care if ISP2 is offline - simply try to send traffic to ISP2 as gateway of last resort and see what happens. If ISP2 is down the traffic will be dropped anyway...

when CLIENT_ACCEPTED { 
    if { [IP::addr [IP::client_addr] 10.10.10.0/24] } then {
         Section for Network 1
        if { [active_members GW_ISP_1_POOL] > 0 } then {
             ISP 1 is online. Use VS default settings and local routing table.
        } else {
             ISP 1 is offline. Setting SNAT IP and Nexthop (aka. routing table overwrite) to ISP2
            snat 222.222.222.10 ; Your IP for ISP2
            nexthop 222.222.222.1   ; Def-GW of ISP2
        }
    } elseif { [IP::addr [IP::client_addr] 10.20.20.0/24] } then {
         Section for Network 2
        if { [active_members GW_ISP_1_POOL] > 0 } then {
             ISP 1 is online. Setting SNAT IP and Nexthop (aka. routing table overwrite) to ISP2
            snat 222.222.222.10 ; Your IP for ISP2
            nexthop 222.222.222.1   ; Def-GW of ISP2
        } else {
             ISP 1 is offline. Reject access for Network 2.
            reject
        }
    } else {
         Undefined traffic will use VS default settings...
    } 
}

Note: If you utilize the

IP-Forwarding

snat

nexthop

Cheers, Kai