3Com WX3000 Series Operation Manual page 162

1) As shown in Figure
User B, the packet from User A needs to be transmitted to GigabitEthernet 1/0/1. At this time, the
device records the source MAC address of the packet, that is, the address "MAC-A" of User A to
the MAC address table of the switch, forming an entry shown in
Figure 1-1 MAC address learning diagram (1)
Figure 1-2 MAC address table entry of the switch (1)
MAC-address
MAC-A GigabitEthernet1/0/1
2) After learning the MAC address of User A, the device starts to forward the packet. Because there is
no MAC address and port information of User B in the existing MAC address table, the device
forwards the packet to all ports except GigabitEthernet 1/0/1 to ensure that User B can receive the
packet.
Figure 1-3 MAC address learning diagram (2)
3) Because the device broadcasts the packet, both User B and User C can receive the packet.
However, User C is not the destination device of the packet, and therefore does not process the
packet. Normally, User B will respond to User A, as shown in
packet from User B is sent to GigabitEthernet 1/0/4, the device records the association between
the MAC address of User B and the corresponding port to its MAC address table.
1-1, User A and User B are both in VLAN 1. When User A communicates with
Port VLAN ID
1
1-2
Figure 1-2.
Figure 1-4. When the response