Use-case scenarios for VLAN tagging.
Three common real-life scenarios where customers can leverage the capabilities of VLAN tagging are as follows:
- Broadcast domains and network security—VLANs are essentially broadcast domains that do not need to be defined by a physical location. You can create VLANs for specific departments within your organization and limit access to those particular VLANs. When used in conjunction with Access Control Lists, (ACLs), you can control a user’s network access within a VLAN itself. With the port customization of Layer-2 switches, VLANs provide an inherent level of security and control to your network.
- Separate services from data—especially useful with large network environments, customers can move all critical services, such as DNS and DHCP, onto their own VLAN, isolating services from the main data VLANs of your organization, safeguarding against power failures and outages, and allowing for portability of the virtual IP space.
- Prioritize traffic through 802.1P—in most business environments it is often desirable to give core services a higher priority through the network. For example, an organization may want to isolate all VOIP related traffic, which is real-time, from data from the traffic of its users workstations due to the different QOS requirements for each. This ensures critical services are maintained.
- Consolidation—as older DNS and DHCP servers are retired, it is sometimes difficult to know which clients are configured with the IP addresses of the older servers. Adding the IP address of the old DNS or DHCP servers to the VLAN of active DNS/DHCP Server allows clients to continue to use the configured IP addresses without disruption to the network.