Most probably, the port is still emitting the so-called LOOP frames to detect a self-looped port. These frames are sent approximately once per minute, and both their source and destination is the MAC address of the originating port. This may be the reason why your customer can see your Fa1/1 MAC address on his equipment.
There is nothing to worry about. And by the way, the Wireshark utility can not elicit a response from your Fa1/1 port. It is a passive network scanner.
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...