3Com Switch 4210 9-Port, Configuration Manual

Page: 134 / 567

132 C
HAPTER
13: MAC A
DDRESS
T
ABLE
M
ANAGEMENT
packet, that is, the address "MAC-A" of User A to the MAC address table of the
switch, forming an entry shown in Figure 42.
Figure 41 MAC address learning diagram (1)
Figure 42 MAC address table entry of the switch (1)
2 After learning the MAC address of User A, the switch starts to forward the packet.
Because there is no MAC address and port information of User B in the existing
MAC address table, the switch forwards the packet to all ports except Ethernet
1/0/1 to ensure that User B can receive the packet.
Figure 43 MAC address learning diagram (2)
3 Because the switch 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
Figure 44. When the response packet from User B is sent to Ethernet 1/0/4, the
Eth1/0/1
Eth1/0/3 Eth1/0 /4
User A
User B User C
Port VLAN ID MAC-address
Ethernet1/0/1 1 MAC-A
Eth1/0/1
Eth1/0/3 Eth1/0 /4
User A
User B User C