 Eventually, the accumulated broadcasts exhaust the egress capacity of the links, the switch begins dropping frames, and communication across the switch becomes unreliable or even impossible.Switching loops can cause misleading entries in a switch's media access control (MAC) database and can cause endless unicast frames to be broadcast throughout the network.A loop can make a switch receive the same broadcast frames on two different ports, and alternatingly associate the sending MAC address with the one or the other port.