Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 749

44 Private VLANs (PVLAN) Private VLANs (PVLANs) extend Dell Networking OS security suite by providing Layer 2 isolation between ports within the same virtual local area network (VLAN). A PVLAN partitions a traditional VLAN into subdomains identified by a primary and secondary VLAN pair. Private VLANs block all traffic to isolated ports except traffic from promiscuous ports. Traffic received from an isolated port is forwarded only to promiscuous ports or trunk ports. Example uses of PVLANs: • A hotel can use an isolated VLAN in a PVLAN to provide Internet access for its guests, while stopping direct access between the guest ports. • A service provider can provide Layer 2 security for customers and use the IP addresses more efficiently, by using a separate community VLAN per customer and at the same time using the same IP subnet address space for all community and isolated VLANs mapped to the same primary VLAN. - In more detail, community VLANs are especially useful in the service provider environment because multiple customers are likely to maintain servers that must be strictly separated in customer-specific groups. A set of servers owned by a customer could comprise a community VLAN, so that those servers could communicate with each other, and would be isolated from other customers. Another customer might have another set of servers in another community VLAN. Another customer might want an isolated VLAN, which has one or more ports that are also isolated from each other. For complete syntax information about the commands described in this chapter, refer to the Private VLANs chapter in the Dell Networking OS Command Line Reference Guide. Topics: • Private VLAN Concepts • Using the Private VLAN Commands • Configuration Task List • Private VLAN Configuration Example • Inspecting the Private VLAN Configuration Private VLAN Concepts Review the following PVLAN concepts before you create PVLANs on your system. The VLAN types in a PVLAN include: • Community VLAN - a type of secondary VLAN in a primary VLAN: - Ports in a community VLAN can communicate with each other. - Ports in a community VLAN can communicate with all promiscuous ports in the primary VLAN. - A community VLAN can only contain ports configured as host. • Isolated VLAN - a type of secondary VLAN in a primary VLAN: - Ports in an isolated VLAN cannot talk directly to each other. - Ports in an isolated VLAN can only communicate with promiscuous ports in the primary VLAN. - An isolated VLAN can only contain ports configured as host. • Primary VLAN - the base VLAN of a PVLAN: - A switch can have one or more primary VLANs, and it can have none. - A primary VLAN has one or more secondary VLANs. Private VLANs (PVLAN) 749