That is perfectly correct behaviour and is considered the process of "filtering" in bridging/switching terminology. Consider the following example: you have an ethernet hub connected to port 0/1 of a switch. There are two devices on the hub, with MAC addresses A and B. If A sends a frame to packet B, then the hub will forward that frame to all other ports on the hub (which is how hubs work), which means it will get to B. It will also reach the switch on port 0/1. There is no need for the switch to forward the frame anywhere since B has already received it.
This is a fairly old issue but could not help knowing how the switch would know that the B wiil receive the frame. Only way switch would know is to check its CAM to see whether the B is in the CAM. Will the switch has a list of all the MACs of devices attached to the HUB. Is so how would it(switch) learn/build its CAM to include those addresses.
[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...