Load balance based on the source IP addresses 4th octet

there are more odds than 3,5, 7 and 9.

To detect if something is even or odd you should use modulus.

pseudo code: if { $X%2 } { odd } else { even }

For example:

 cat test.tcl

if { 1025%2 } { puts "odd" } else { puts  "even" }
if { 666%2 } { puts "odd" } else { puts  "even" }

 tclsh test.tcl

odd
even