Can't run league, fire wall

Sometimes, when i start to connect to a game, the infamous fire wall pops up and doesn't let me play. I've tried re-starting my computer, running as administrator, and re launching league. As of right now, (as I'm originally typing this) i had to abandon a game because simply i cannot join. This has happened many times before and i don't think i should be banned for something that i can't control. Please help, and thank you in advance.