I have a named instance of MS SQL Server 2008 running on port 1456. TCP/IP and NamedPipes are ENABLED for the server. No Aliases created.
local address: 192.168.1.123\RM - works from local computer and local subnet (no ports specified when connecting)
local name: my-server\RM - works from local computer and local subnet (no ports specified when connecting)
remote address (thru the router): 188.8.131.52,1456\RM - DOES NOT WORK from local or remote networks. I get "login failed" error, all because I hit the DEFAULT instance all the time, which is SQL 2005 (works fine).
Port forwarding on the router is setup. Port 1456 is open.