Chapter 9 Interfaces
NXC Series User’s Guide
159
9.3 VLAN Interfaces
A Virtual Local Area Network (VLAN) divides a physical network into multiple logical networks. The
standard is defined in IEEE 802.1q.
Note: By default, the NXC acts a bridge device. This means all interfaces (ge1~g6) are
grouped together into a single VID, vlan0. Also note that vlan0 cannot be removed
and the VID cannot be changed.
Figure 88 Example: Before VLAN
In this example, there are two physical networks and three departments A, B, and C. The physical
networks are connected to hubs, and the hubs are connected to the router.
Alternatively, you can divide the physical networks into three VLANs.
Figure 89 Example: After VLAN
Each VLAN is a separate network with separate IP addresses, subnet masks, and gateways. Each VLAN
also has a unique identification number (ID). The ID is a 12-bit value that is stored in the MAC header. The
VLANs are connected to switches, and the switches are connected to the router. (If one switch has
enough connections for the entire network, the network does not need switches A and B.)
• Traffic inside each VLAN is layer-2 communication (data link layer, MAC addresses). It is handled by
the switches. As a result, the new switch is required to handle traffic inside VLAN 2. Traffic is only
broadcast inside each VLAN, not each physical network.
• Traffic between VLANs (or between a VLAN and another type of network) is layer-3 communication
(network layer, IP addresses). It is handled by the router.
To Next Page
Loading...
