switch & swith -globe question

when CLIENT_DATA {
set pay1 [TCP::payload 8]
binary scan $pay1 IA4 len1 trx1

if { [IP::addr [IP::client_addr] equals "x.x.x.x/24" ] } {
switch -glob $trx1 {
"A" { do something }
"B" { do something }
"C" { do something }
default { do something else }
}
}
elseif { [IP::addr [IP::client_addr] equals "y.y.y.y/24" ] } {
switch -glob $trx1 {
"D" { do something }
"E" { do something }
"F" { do something }
default { do something else }
}
}
}