Configuring VLANs
Configuring Uplink Ports Within a Port-Based VLAN
You can configure a subset of the ports in a port-based VLAN as uplink ports. When you configure uplink ports in a port-based VLAN, the device sends all broadcast and unknown-unicast traffic from a port in the VLAN to the uplink ports, but not to other ports within the VLAN. Thus, the uplink ports provide tighter broadcast control within the VLAN.
For example, if two ports within a port-based VLAN are Gigabit ports attached to the network and the other ports in the VLAN are 10/100 ports attached to clients, you can configure the two ports attached to the network as uplink ports. In this configuration, broadcast and unknown-unicast traffic in the VLAN does not go to all ports in the VLAN. The traffic goes only to the uplink ports. The clients on the network do not receive broadcast and unknown-unicast traffic from other ports, including other clients.
To configure uplink ports in a port-based VLAN, use the following CLI method.
USING THE CLI
To configure a port-based VLAN containing uplink ports, enter commands such as the following:
HP9300(config)# vlan 10 by port
HP9300(config-vlan-10)# untag ethernet 1/1 to 1/24
HP9300(config-vlan-10)# untag ethernet 2/1 to 2/2
HP9300(config-vlan-10)# uplink-switch ethernet 2/1 to 2/2
Syntax: [no] uplink-switch ethernet <portnum> [to <portnum> ethernet <portnum>]
In this example, 24 ports on a 10/100 module and two Gigabit ports on a Gigabit module are added to port-based VLAN 10. The two Gigabit ports are then configured as uplink ports.
USING THE WEB MANAGEMENT INTERFACE
You cannot configure uplink ports in a port-based VLAN using the Web management interface.
Configuring the Same IP Sub-Net Address on Multiple Port-Based VLANs
For a device to route between port-based VLANs, you must add a virtual interface to each VLAN. Generally, you also configure a unique IP sub-net address on each virtual interface. For example, if you have three port-based VLANs, you add a virtual interface to each VLAN, then add a separate IP sub-net address to each virtual interface. The IP address on each of the virtual interfaces must be in a separate sub-net. The device routes Layer 3 traffic between the sub-nets using the sub-net addresses.
NOTE: This feature applies only to the HP 9304M, HP 9308M, and HP 6308M-SX routing switches.
Figure 16.14 shows an example of this type of configuration.
