mIRC's UPnP support does not work at all for me, and I too have the error "* /localinfo: unable to resolve local host" upon entering "/localinfo -p".
I have figured out why this is happening. mIRC is calling CStaticPortMappingCollection::Add() with L"127.0.0.1" as the fourth parameter, when it should be calling it with the local IP address of the interface the router is connected to (usually 192.168.x.x). Calling it with 127.0.0.1 is causing Windows to put the Computer Name (i.e., the thing set in Control Panel -> System -> Computer Name) between the tags <NewInternalClient> and </NewInternalClient> in the UPnP command sent to the router, instead of the local IP address which is what should be in there. As a result, my router is replying with "HTTP/1.1 500 Internal Server Error" instead of "HTTP/1.1 200 OK" as it should be. And my router's log gets the entry "miniupnpd[___]: Failed to convert hostname '________' to ip address" added to it, where '________' is my Computer Name and "[___]" is the process ID of miniupnpd on the router.
Other applications work fine with UPnP on my setup, and I have verified that the only difference between the ones that work and mIRC, which doesn't, is mIRC's use of "127.0.0.1" as the address instead of the proper local IP address of the interface the router is connected to.
I would speculate that only routers with a broken UPnP implementation are working with mIRC's UPnP support.
Last edited by Deadcode; 22/10/13 10:25 PM.
