The local area network does not connect

Our school is with that butterfly surfer, our dormitory has 7 machines, changes planes with 8 fellatios connects together, has used well, but on sudden one day of local area network on, CS, the evil spirit beast on-line game could not play together completely continually, but might access the net, did not know completely any reason .IP was the manual disposition, was only, could not change.The firewall does not have the question, any establishment has not changed.The poison has also killed, does not have, should impossible be poisonous, should for be at the same time 7 machines does not link mutually.May ping obtain mutually with the ping words, invite under the fellow chivalrous people publication the opinion