I am experiencing strange behavior in my network. It occurs in Layer2 part of the network (it consists of Cisco 7600, 6500, 3560, 2960 and some wireless antennas). The MPLS and L3 part of network are fine. It seems that some packets are replicated in network. I have occasional storms of unicast flooding. Some unicast packets are multiplicated and due to CAM table flashing they are flooded to all ports.
What could cause multiplicating packets in layer 2 netowrk (1 sent unicast packet replicated 10000 times). Has anyone had problem like that? If there is layer 2 loop in my network than I would have broadcats storm, which is not the case.
Whit sniffer i.e. I can see 170000 DNS replys to same IP address (the same vallid src and dst MAC and IP address so it shouldn't be DOS attack). Also from DNS server to network are sent only one DNS reply.
Also I send 1 ping and then receive back 1000 replys!. I can see on traffic graph that some wireless antennas are sending back traffic that they received.
any help would ne appreciated
Thanks in advance.