VLAN Security

If you set up a virtual local area network (VLAN), remember that VLANs share bandwidth on a network and require additional security measures.

• Define VLANs to separate sensitive clusters of systems from the rest of the network. This decreases the likelihood that users will gain access to information on these clients and servers.

• Assign a unique native VLAN number to trunk ports.

• Limit the VLANs that can be transported over a trunk to only those that are strictly required.

• Disable VLAN Trunking Protocol (VTP), if possible. Otherwise, set the following for VTP: management domain, password, and pruning. Then set VTP into transparent mode.