Well, I just did. Netalyzr said "OK" for every test he did.
I thought there could be some problem with LoL Client specific UDP port so I've put my PC's IP as DMZ on router, what means that ALL ports are Open. And yes, I tested, they are really opened. But still, nothing changed, the LoL client doesn't connect (or reconnect) to the game.
Just to keep feeding you with more info, the problem is still happening right now.
edit: for a couple of hours now, i've been able to play properly.
No Reverse Information / 126.96.36.199 Recorded at 04:49 EDT (08:49 UTC), Mar 30 2010. Permalink. Client/server transcript.
Summary of Noteworthy Events –
© 2013 Riot Games, Inc. All rights reserved. Riot Games, League of Legends and PvP.net are trademarks, services marks, or registered trademarks of Riot Games, Inc.