@G777 Much quicker than the accepted solution: Turn on the NAT-DMZ. I'm on an ER-605 but I believe this is similar to the posted item. Transmission -> NAT -> NAT-DMZ + Add a DMZ entry going to any IP...

@G777 There's a slightly better way to finish this off. I'm on an ER-605 which also follows the strict letter of the Internet spec and has all ports closed by default. Adding in a DMZ server lets you...