Vlan Summary - ZyXEL Communications NXC2500 User Manual

Figure 67 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.
This approach provides a few advantages.
• Increased performance - In VLAN 2, the extra switch should route traffic inside the sales
department faster than the router does. In addition, broadcasts are limited to smaller, more
logical groups of users.
• Higher security - If each computer has a separate physical connection to the switch, then
broadcast traffic in each VLAN is never sent to computers in another VLAN.
• Better manageability - You can align network policies more appropriately for users. For example,
you can create different policy route rules for each VLAN (each department in the example
above), and you can set different bandwidth limits for each VLAN. These rules are also
independent of the physical network, so you can change the physical network without changing
policies.
In this example, the new switch handles the following types of traffic:
• Inside VLAN 2.
• Between the router and VLAN 1.
• Between the router and VLAN 2.
• Between the router and VLAN 3.

8.3.1 VLAN Summary

This screen lists every VLAN interface. If you enabled IPv6 in the Configuration > System > IPv6
screen, you can also configure VLAN interfaces used for your IPv6 networks on this screen. To
access this screen, click Configuration > Network > Interface > VLAN.
Chapter 8 Interfaces
A
B
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