Vlan Overview - Dell Broadcom NetXtreme Family of Adapters User Manual

Virtual LANs: Broadcom NetXtreme II Network Adapter User Guide
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Virtual LANs: Broadcom NetXtreme II Network Adapter User
Guide

VLAN Overview

Adding VLANs to Teams
VLAN Overview
Virtual LANs (VLANs) allow you to split your physical LAN into logical parts, to create logical segmentation of workgroups, and
to enforce security policies for each logical segment. Each defined VLAN behaves as its own separate network with its traffic
and broadcasts isolated from the others, increasing bandwidth efficiency within each logical group. Up to 64 VLANs (63
tagged and 1 untagged) can be defined for each Broadcom adapter on your server, depending on the amount of memory
available in your system.
VLANs can be added to a team to allow multiple VLANs with different VLAN IDs. A virtual adapter is created for each VLAN
added.
Although VLANs are commonly used to create individual broadcast domains and/or separate IP subnets, it is sometimes
useful for a server to have a presence on more than one VLAN simultaneously. Broadcom adapters support multiple VLANs on
a per-port or per-team basis, allowing very flexible network configurations.
Figure 1: Example of Servers Supporting Multiple VLANs with Tagging
Figure 1 shows an example network that uses VLANs. In this example network, the physical LAN consists of a switch, two
servers, and five clients. The LAN is logically organized into three different VLANs, each representing a different IP subnet.
The features of this network are described in
Table 1: Example VLAN Network Topology
Component Description
VLAN #1 An IP subnet consisting of the Main Server, PC #3, and PC #5. This subnet represents an engineering group.
Includes the Main Server, PCs #1 and #2 via shared media segment, and PC #5. This VLAN is a software
VLAN #2
development group.
VLAN #3 Includes the Main Server, the Accounting Server and PC #4. This VLAN is an accounting group.
A high-use server that needs to be accessed from all VLANs and IP subnets. The Main Server has a Broadcom
adapter installed. All three IP subnets are accessed via the single physical adapter interface. The server is
attached to one of the switch ports, which is configured for VLANs #1, #2, and #3. Both the adapter and the
Main Server
connected switch port have tagging turned on. Because of the tagging VLAN capabilities of both devices, the
server is able to communicate on all three IP subnets in this network, but continues to maintain broadcast
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Table 1.