HP 2500 manual Example of Routing Between VLANs via an External Router

Configuring Advanced Features

Port-Based Virtual LANs (Static VLANs)

saved by not allowing packets to flood out all ports. An external router is required to enable separate VLANs on a switch to communicate with each other.

For example, referring to figure 9-39, if ports 1 through 4 belong to VLAN_1 and ports 5 through 8 belong to VLAN_2, traffic from end-node stations on ports 2 through 4 is restricted to only VLAN_1, while traffic from ports 5 through 7 is restricted to only VLAN_2. For nodes on VLAN_1 to communicate with VLAN_2, their traffic must go through an external router via ports 1 and 8.

	Switch with Two
	VLANs Configured
		VLAN_1	Port 2
			Port 3
	Port 1		Port 4
External
Router			Port 5
	Port 8
			Port 6
			Port 7
		VLAN_2

Figure 9-39. Example of Routing Between VLANs via an External Router

Overlapping (Tagged) VLANs. A port on the Series 2500 switches can be a member of more than one VLAN if the device to which they are connected complies with the 802.1Q VLAN standard. For example, a port connected to a central server using a network interface card (NIC) that complies with the 802.1Q standard can be a member of multiple VLANs, allowing members of multiple VLANs to use the server. Although these VLANs cannot communicate with each other through the server, they can all access the server over the same connection from the switch. Where VLANs overlap in this way, VLAN “tags” are used to distinguish between traffic from different VLANs.

Features Configuring Advanced

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