Intel 480T, User Manual

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C H A P T E R 5 Virtual LANs (VLANs)
• The server connected to port 9 on System 1 has a NIC that
supports 802.1Q tagging.
• The server connected to port 9 on System 1 is a member of both
VLAN
Marketing and VLAN Sales .
• All other stations use untagged traffic.
As data passes out of the switch, the switch determines if the
destination port requires the frames to be tagged or untagged. All
traffic coming from and going to the server is tagged. Traffic
coming from and going to the trunk ports is tagged. The traffic that
comes from and goes to the other stations on this network is not
tagged.
Mixing Port-Based and Tagged VLANs
You can configure the switch using a combination of port-based and
tagged VLANs. A given port can be a member of multiple VLANs,
with the stipulation that only one of its VLANs uses untagged
traffic. In other words, a port can simultaneously be a member of
one port-based VLAN and multiple tag-based VLANs.
For the purposes of VLAN classification, packets arriving on a port
with an 802.1Q tag containing a VLANid of zero are treated as
untagged.
Protocol-Based VLANs
Protocol-based VLANs enable you to define a packet filter that the
switch uses as the matching criteria to determine if a particular
packet belongs to a particular VLAN.
Protocol-based VLANs are most often used in situations where
network segments contain hosts running multiple protocols. For
example, in Figure 10, the hosts are running both the IP and
NetBIOS protocols.
The IP traffic has been divided into two IP subnets, 192.207.35.0
and 192.207.36.0. The subnets are internally routed by the switch.
The subnets are assigned different VLAN names,
Finance and
Personnel , respectively. The remainder of the traffic belongs to the
VLAN named MyCompany . All ports are members of the VLAN
MyCompany .