Vlan Implementation - D-Link DFL-1600 User Manual

58 Chapter 9. Interfaces
bytes
8 6 6 4 2 46 4
to
1500
Pre- Dest. Sou- Len- Data CRC
amble rce 32 bits gth
16 3 1 12
VLAN Pri- CFI VID
Type ority
Indicator
(0x8100)
VLAN Tag
Table 9.1: 802.1Q Standard Ethernet Frame.
9.2.3

VLAN Implementation

Comply to 802.1Q standard, the D-Link firewall implement VLAN by
defining one or more VLAN interfaces on it using a unique VID for each
VLAN. When Ethernet frames are received by the firewall, they are
examined for the VID. If a VID is found, and a matching VID interface has
been defined, the firewall will be able to recognize the membership and
destination of that VLAN communication.
VLANs in D-Link firewalls are useful in several different scenarios, for
instance, when firewall filtering is needed between different departments in
an organization, or when the number of interfaces needs to be expanded.
D-Link Firewalls User's Guide