There is a problem with ip packing at mikrotik version's 6.x, and between mikrotik version 5.x and version 6.x . when ip packing used between mikrotik version's 5.x there is no problems. ip packing works in all the above variants, and not noticed a problem in the rest of the network on both sides. The problem is that when ip packing is on, its not possible to approach from the opposite side of network to Mikrotik router, neither over winbox or via the web if some of the ip packing connected router a with MikroTik version 6.x . Inaccessible mikrotik router works ok, it is possible to ping them and get to him via mac telnet but not over winbox or Web. Its look like minor problem but its very irritating please consider and fix.