Here is my regex
        my ( $peer, $ip, $type, $mask, $port, $status ) = ( $line =~ /
                ^               # Start of line
                ([\w\d\-_\.]+)  # First capture, peer name
                \/?\s+?         # Optional trailing slash, optional space
                \(?             # Optional opening parenthesis
                ([\w\d\.]+)     # Second capture, IP address
                \)?             # Optional closing parenthesis
                \s+?\(?         # Optional space, optional open parenthesis
                ([\w]+)         # Third capture, type
                \)?\s+?         # Optional closing parenthesis, optional space
                ([\d\w\.]+)     # Forth capture, mask
                \s+?            # Optional space
                ([\d\w\.]+)     # Fifth capture, port
                \s+?            # Optional space
                ([\d\w\.]+)     # Final capture, status
                $               # End of line
        /x );

Works with this:
rpc-pbx-per-01/  10.46.26.252    (S)  255.255.255.255  4569          UNREACHABLE

Does not work with this:
rpc-pbx-glb-01/  (Unspecified)   (S)  255.255.255.255  4569          UNKNOWN