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craig_m_254946's avatar
craig_m_254946
Icon for Nimbostratus rankNimbostratus
Mar 17, 2016

iRule to restrict TCP and UDP to the same range of ports.

Like the title says, I'm trying to make an iRule to restrict ports to a VS.

 

I was trying to use the following, but getting an error. when CLIENT_ACCEPTED { if {([TCP::local_port] >= 10514 ) && ([TCP::local_port] <= 10526) || ([TCP::local_port] >= 514 ) && ([TCP::local_port] <= 515) } { pool Pool_Name } elseif {([UDP::local_port] >= 10514 ) && ([UDP::local_port] <= 10526) || ([UDP::local_port] >= 514 ) && ([UDP::local_port] <= 515) } { pool Pool_Name } else reject }

 

The error doesn't help me understand where my mistake is. 01070151:3: Rule [/Common/SPL-PRD-SYS-restricted] error: /Common/SPL-PRD-SYS-restricted:6: error: [undefined procedure: elseif][elseif {([UDP::local_port] >= 10514 ) && ([UDP::local_port] <= 10526) || ([UDP::local_port] >= 514 ) && ([UDP::local_port] <= 515) } { pool Pool_Name } else reject]

 

Thanks

 

BIG-IP
security

2 Replies

  • Patrik_Jonsson's avatar
    Patrik_Jonsson
    Icon for MVP rankMVP
    Mar 17, 2016

    You're missing some curly brackets. Try this:

    when CLIENT_ACCEPTED {
    if {([TCP::local_port] >= 10514 ) && ([TCP::local_port] <= 10526) || ([TCP::local_port] >= 514 ) && ([TCP::local_port] <= 515) } {
        pool Pool_Name
    } elseif {([UDP::local_port] >= 10514 ) && ([UDP::local_port] <= 10526) || ([UDP::local_port] >= 514 ) && ([UDP::local_port] <= 515) } {
        pool Pool_Name
    } else {
        reject
    }
}

    /Patrik

  • Patrik_Jonsson's avatar
    Patrik_Jonsson
    Icon for MVP rankMVP
    Mar 17, 2016

    I might do it like this instead as it's easier to read.

    when CLIENT_ACCEPTED {

    Check which protocol and set the port variable
    if { [IP::protocol] == 6 } {
        6 means TCP
        set port [TCP::local_port]
    } elseif { [IP::protocol] == 17 } {
        17 means UDP
        set port [UDP::local_port]
    } else {
        Unhandled protocol
        set port 0
    }

    Make sure the ports are between 10514 and 10526 OR 514, the select the pool
    if { ($port >= 10514 && $port <= 10526) || $port == 514 } {
        pool Pool_Name
    } else {
        reject
    }
}

    /Patrik