1-6 
Table 1-1 Packet processing of an access port 
Processing of an incoming packet 
For an untagged packet  For a tagged packet 
Processing of an 
outgoing packet 
Receive the packet and tag 
the packet with the default 
VLAN tag. 
z  If the VLAN ID is just the default VLAN 
ID, receive the packet. 
z  If the VLAN ID is not the default VLAN 
ID, discard the packet. 
Strip the tag from the 
packet and send the 
packet. 
 
Table 1-2 Packet processing of a trunk port 
Processing of an incoming packet 
For an untagged packet  For a tagged packet 
Processing of an outgoing 
packet 
z  If the port has already been 
added to its default VLAN, tag 
the packet with the default 
VLAN tag and then forward 
the packet. 
z  If the port has not been added 
to its default VLAN, discard 
the packet. 
z  If the VLAN ID is one of the 
VLAN IDs allowed to pass 
through the port, receive the 
packet. 
z  If the VLAN ID is not one of 
the VLAN IDs allowed to 
pass through the port, 
discard the packet. 
z  If the VLAN ID is just the 
default VLAN ID, strip off 
the tag and send the 
packet. 
z  If the VLAN ID is not the 
default VLAN ID, keep 
the original tag 
unchanged and send the 
packet. 
 
Table 1-3 Packet processing of a hybrid port 
Processing of an incoming packet 
For an untagged packet  For a tagged packet 
Processing of an outgoing 
packet 
z  If the port has already been 
added to its default VLAN, 
tag the packet with the 
default VLAN tag and then 
forward the packet. 
z  If the port has not been 
added to its default VLAN, 
discard the packet. 
z  If the VLAN ID is one of the 
VLAN IDs allowed to pass 
through the port, receive the 
packet. 
z  If the VLAN ID is not one of 
the VLAN IDs allowed to 
pass through the port, 
discard the packet. 
Send the packet if the VLAN ID 
is allowed to pass through the 
port. Use the port hybrid vlan 
command to configure whether 
the port keeps or strips off the 
tags when sending packets of a 
VLAN (including the default 
VLAN).