Hi Aguley,
if using a single Virtual Server for both ports you need to evaluate the port number to selectivly redirect the request.
if { [TCP::local_port] eq 57701 } then {
do nothing
} elseif { [TCP::local_port] eq 50100 } then {
HTTP::redirect "https://abc.com:57701/irj/portal"
}
If using independent Virtual Server for each port you don't need to evalutate the port number. Simply put a...
HTTP::redirect "https://abc.com:57701/irj/portal"
... into the iRule of the Virtual Server listening on port 50100 to redirect every request to the new site.
Cheers, Kai