6.0.3

Table Of Contents
Secure VLANs
Administrators have several options for securing the VLANs in their vSphere environment.
Procedure
1 Ensure that port groups are not congured to VLAN values that are reserved by upstream physical
switches
Do not set VLAN IDs to values reserved for the physical switch.
2 Ensure that port groups are not congured to VLAN 4095 unless you are using for Virtual Guest
Tagging (VGT).
Three types of VLAN tagging exist in vSphere:
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External Switch Tagging (EST)
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Virtual Switch Tagging (VST) - The virtual switch tags with the congured VLAN ID the trac that
is incoming to the aached virtual machines and removes the VLAN tag from the trac that is
leaving them. To set up VST mode, assign a VLAN ID between 1 and 4095.
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Virtual Guest Tagging (VGT) - Virtual machines handle VLAN trac. To activate VGT mode, set
the VLAN ID to 4095. On a distributed switch, you can also allow virtual machine trac based on
its VLAN by using the VLAN Trunking option.
On a standard switch you can congure VLAN networking mode at switch or port group level, and on
a distributed switch at distributed port group or port level.
3 Ensure that all VLANs on each virtual switch are fully documented and that each virtual switch has all
required VLANs and only required VLANs.
Creating a Network DMZ on a Single ESXi Host
One example of how to use ESXi isolation and virtual networking features to congure a secure
environment is the creation of a network demilitarized zone (DMZ) on a single host.
Figure 82. DMZ Configured on a Single ESXi Host
hardware network
adapter 1
External Network Internal Network
hardware network
adapter 2
ESXi
Virtual Machine
1
firewall server web server application server firewall server
Standard
Switch 1
Standard
Switch 2
Standard
Switch 3
Virtual Machine
2
Virtual Machine
3
Virtual Machine
4
In this example, four virtual machines are congured to create a virtual DMZ on Standard Switch 2:
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Virtual Machine 1 and Virtual Machine 4 run rewalls and are connected to physical network adapters
through standard switches. Both of these virtual machines are using multiple switches.
vSphere Security
236 VMware, Inc.