HP ProCurve 9304M Installation And Configuration Manual page 286

Installation and Basic Configuration Guide
Untagged Port Using VLAN 2 as Port Native VLAN
Figure 8.37 shows an example in which a port's Port Native VLAN is not VLAN 1. In this case, VLAN 1 uses
tagged frames and VLAN 2 uses untagged frames.
Figure 8.37 Port Native VLAN 2 for untagged BPDUs
To implement this configuration, enter the following commands.
Commands on the HP Device
HP9300(config)# default-vlan-id 4000
HP9300(config)# vlan 1
HP9300(config-vlan-1)# tagged ethernet 1/1
HP9300(config-vlan-1)# exit
HP9300(config)# vlan 2
HP9300(config-vlan-2)# tagged ethernet 1/1
HP9300(config-vlan-2)# exit
HP9300(config)# interface ethernet 1/1
HP9300(config-if-1/1)# dual-mode 2
HP9300(config-if-1/1)# pvst-mode
HP9300(config-if-1/1)# exit
These commands change the default VLAN ID, configure port 1/1 as a tagged member of VLANs 1 and 2, and
enable the dual-mode feature and PVST+ support on port 1/1. Since VLAN 1 is tagged in this configuration, the
default VLAN ID must be changed from VLAN 1 to another VLAN ID. Changing the default VLAN ID from 1 allows
the port to process tagged frames for VLAN 1. VLAN 2 is specified with the dual-mode command, which makes
VLAN 2 the port's Port Native VLAN. As a result, the port processes untagged frames and untagged PVST
BPDUs on VLAN 2.
NOTE: Although VLAN 2 becomes the port's untagged VLAN, the CLI still requires that you add the port to the
VLAN as a tagged port, since the port is a member of more than one VLAN.
Port 1/1 will process BPDUs as follows:
• Process IEEE 802.1Q BPDUs for VLAN 1.
• Process untagged PVST BPDUs for VLAN 2.
• Drop tagged PVST BPDUs for VLAN 1.
Note that when VLAN 1 is not the default VLAN, the ports must have the dual-mode featured enabled in order to
process IEEE 802.1Q BPDUs.
For example, the following configuration is incorrect:
HP9300(config)# default-vlan-id 1000
HP9300(config)# vlan 1
HP9300(config-vlan-1)# tagged ethernet 1/1 to 1/2
HP9300(config-vlan-1)# exit
HP9300(config)# interface ethernet 1/1
HP9300(config-if-1/1)# pvst-mode
HP9300(config-if-1/1)# exit
HP9300(config)# interface ethernet 1/2
HP9300(config-if-1/2)# pvst-mode
HP9300(config-if-1/2)# exit
8 - 80
Untagged IEEE BPDU for VLAN 1
Tagged PVST BPDU for VLAN 1
Untagged PVST BPDU for VLAN 2
Port 1/1
Cisco
device
Port 3/2