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On port-
based VLAN
, NICs do not need to be able to identify 802.1Q tags in packet headers. NICs send and receive
normal Ethernet packets. If the packet's destination lies on the same segment, communications take place using normal
Ethernet protocols. Even though this is always the case, when the destination for a packet lies on another switch port,
VLAN considerations come into play to decide if the packet is dropped by the Switch or delivered.
IEEE 802.1Q Tag-based VLAN
IEEE 802.1Q (tagged) VLAN
is implemen
ted on the Switch. 802.1Q VLAN require
s tagging, which enables them to span
the entire network (assuming all switches on the network are IEEE 802.1Q-compliant).
VLAN allow a network to be segmented in order to reduce the size of broadcast domains. All packets entering a VLAN will
only be forwarded to the stations (over IEEE 802.1Q enabled switches) that are members of that VLAN, and this includes
broadcast, multicast and unicast packets from unknown sources.
VLAN can also provide a level of security to your network. IEEE 802.1Q VLAN will only deliver packets between stations
that are members of the VLAN. Any port can be configured as either tagging or untagging. The untagging feature of IEEE
802.1Q VLAN allows VLAN to work with legacy switches that don't recognize VLAN tags in packet headers. The tagging
feature allows VLAN to span multiple 802.1Q
-compliant switches through a single physical connection and allows
Spanning Tree to be enabled on all ports and work normally.
Any port can be configured as eith
er tagging or untagging. The untagging feature of IEEE 802.1Q VLAN allows VLAN to
work with legacy switches that don’t recognize VLAN tags in packet headers. The tagging feature allows VLAN to span
multiple 802.1Q-compliant switches through a single physical connection and allows Spanning Tree to be enabled on all
ports and work normally.
Some relevant terms:
Tag -
The act of putting 802.1Q VLAN information into the header of a packet.
Untag -
The act of stripping 802.1Q VLAN information out of the packet
header.
1.
No matter what basis is used to uniquely identify end nodes and assign these nodes VLAN
membership, packets cannot cross VLAN without a network device performing a routing
function between the VLAN.
2.
The PoE Web Smart Switch supports IEEE 802.1Q
VLAN. The port untagging function can be
used to remove the 802.1 tag from packet headers to maintain compatibility with devices that
are tag-unaware.
3.
The PoE Web Smart Switch
's default is to assign all ports to a single 802.1Q VLAN named
DEFAULT_VLAN. As
new VLAN is created, the member ports assigned to the new VLAN will
be removed from the DEFAULT_ VLAN port member list. The DEFAULT_VLAN has a VID = 1.
