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

Forum Discussion

Burrell's avatar
Burrell
Icon for Nimbostratus rankNimbostratus
Feb 18, 2016

Help with iRule Port Switch statement

I have an application with 2 nodes running 4 discrete services across a group of 4 pool ranges. I have configured a FastL4 vs with port 0 and use an iRule switch to match the port and select the c...
application delivery
devops
irules
LTM
Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Feb 18, 2016

Hi Burrell,

its kinda complicated to match port-ranges using the 

[switch]
command, so you may try a 
[if]
based sytax as outlined below...

when CLIENT_ACCEPTED {
    if { ( [TCP::local_port] >= 26000 ) and ( [TCP::local_port] <= 26009 ) } then {
        pool RTS_PROD_pool1
    } elseif { ( [TCP::local_port] >= 26500 ) and ( [TCP::local_port] <= 26509 ) } then {
        pool RTS_PROD_pool2
    } elseif { ( [TCP::local_port] >= 27000 ) and ( [TCP::local_port] <= 27009 ) } then {
        pool RTS_PROD_pool3
    } elseif { ( [TCP::local_port] >= 27500 ) and ( [TCP::local_port] <= 27509 ) } then {
        pool RTS_PROD_pool4 
    } else {
        reject
    }
}

Cheers, Kai