System network
Adding VLAN subinterfaces
FortiGate-100A Administration Guide
01-28007-0068-20041203
67
If the network uses IEEE 802.1 VLAN tags to segment your network traffic, you can
configure a FortiGate unit operating in Transparent mode to provide security for
network traffic passing between different VLANs. To support VLAN traffic in
Transparent mode, you add virtual domains to the FortiGate unit configuration. A
virtual domain consists of two or more VLAN subinterfaces or zones. In a virtual
domain, a zone can contain one or more VLAN subinterfaces.
When the FortiGate unit receives a VLAN tagged packet at an interface, the packet is
directed to the VLAN subinterface with matching VLAN ID. The VLAN subinterface
removes the VLAN tag and assigns a destination interface to the packet based on its
destination MAC address. The firewall policies for this source and destination VLAN
subinterface pair are applied to the packet. If the packet is accepted by the firewall,
the FortiGate unit forwards the packet to the destination VLAN subinterface. The
destination VLAN ID is added to the packet by the FortiGate unit and the packet is
sent to the VLAN trunk.
Figure 16: FortiGate unit with two virtual domains in Transparent mode
Figure 17
shows a FortiGate unit operating in Transparent mode and configured with
three VLAN subinterfaces. In this configuration the FortiGate unit could be added to
this network to provide virus scanning, web content filtering, and other services to
each VLAN.
VLAN1
VLAN1
VLAN2
VLAN2
VLAN3
VLAN3
root virtual domain
New virtual domain
Internal
External
VLAN1
VLAN3
VLAN2
VLAN Switch
or router
VLAN Switch or router
VLAN trunk
VLAN1
VLAN2
VLAN3
VLAN trunk
FortiGate unit
VLAN1
VLAN3
VLAN2
Internet
Summary of Contents for FortiGate 100A
Page 12: ...Contents 12 01 28007 0068 20041203 Fortinet Inc ...
Page 24: ...24 01 28007 0068 20041203 Fortinet Inc FortiLog documentation Introduction ...
Page 72: ...72 01 28007 0068 20041203 Fortinet Inc Transparent mode VLAN settings System network ...
Page 80: ...80 01 28007 0068 20041203 Fortinet Inc DHCP IP MAC binding settings System DHCP ...
Page 114: ...114 01 28007 0068 20041203 Fortinet Inc Access profile options System administration ...
Page 232: ...232 01 28007 0068 20041203 Fortinet Inc Profile CLI configuration Firewall ...
Page 244: ...244 01 28007 0068 20041203 Fortinet Inc peergrp Users and authentication ...
Page 276: ...276 01 28007 0068 20041203 Fortinet Inc ipsec vip VPN ...
Page 338: ...338 01 28007 0068 20041203 Fortinet Inc Configuring the banned word list Spam filter ...
Page 356: ...356 01 28007 0068 20041203 Fortinet Inc syslogd setting Log Report ...
Page 374: ...374 01 28007 0068 20041203 Fortinet Inc Index ...