I don't know if you made a typing mistake, but it should be sv_lan 1.
Here's a list of commands for both server and client.
http://www.hl2world.com/wiki/index.php/ ... e_Commands
I normally just fire up the mod, create server (password etc.etc.) once you are in game press esc, find servers click the Lan tab right click on your server in the list and select view server info, where you'll find the ip address. And just give that to your mates along with password. then all they have to do is fire up the mod go to console and I 'think' type connect then the ip address. I think they are promted to enter password. And thats about it. I'm off to check what I have said is correct, man I haven't had anyone else join meh on a lan since early cs dayz)
Also you should be aware that this Mod has options for additional content, like dod,cs,eps1, loast coast,hl source. I'm not sure if there can be a conflict if your running content they havent got or got enabled. If indoubt just check your all on the same. but again I'm not sure.