Dell SmartFabric OS10 User Guide Release 10.5.3

Private VLANs

Private VLANs (PVLANs) enhance the security of Dell SmartFabric OS10 by providing L2 isolation between ports within the same virtual local area network (VLAN). A PVLAN partitions a traditional VLAN in to subdomains identified by primary and secondary VLAN pairs. PVLANs block all traffic to isolated ports except for traffic from promiscuous ports. Traffic received from an isolated port is forwarded only to promiscuous or trunk ports.

Example PVLAN uses:

• Guest access management—The network administrator in a hotel uses an isolated VLAN for providing guest users access to the Internet. Using isolated VLANs restricts direct access between the guest users.
• Service provider networks—Using PVLAN, a service provider can provide L2 security for customers and use IP addresses more efficiently. For example, the service provider can have a separate community VLAN per customer. They can use the same IP subnet address space for all community and isolated VLANs associated with the same primary VLAN.

  Community VLANs are useful in the service provider environment because multiple customers prefer to have servers in strictly separated customer-specific groups. For example, a community VLAN could include a set of servers owned by a customer. These servers could communicate with each other, but would be isolated from other customers. Another customer might have a different set of servers in a different community VLAN. Some customers might want an isolated VLAN, which has one or more ports that are also isolated from each other.