Lucent Technologies P550 - Manual (Page 224)

Using VLANs, Spanning Tree, and Hunt Groups (Layer 2 and Layer 3)
12 -2 Cajun P550/P220 Switch Operation Guide
Note: The switch supports a feature called Automatic VLAN Creation for tagged
frames. When this feature is enabled, the switch creates new VLANs when it
receives packets from previously unknown VLANs.
Forwarding Rules
These rules determine the set of ports on the switch through which members of the
VLAN can be reached. This is called binding a port to a VLAN. A port may be bound to a
VLAN using four methods:
❒ Setting the Port VLAN attribute in the Switch Port Configuration dialog box of the
port form. This identifies the VLAN to which all untagged frames received on the
port are forwarded.
Note: A port has one Port VLAN. Changing this to a new VLAN removes the port
from the old VLAN.
❒ Setting the VLAN Binding attribute in the Switch Port Configuration dialog box to
Bind to All. This causes the port to be bound to all VLANs known to the switch (for
example, all current VLANs and all VLANs added in the future).
❒ Setting the VLAN Binding attribute in the Switch Port Configuration dialog box to
Bind to Received. This causes the port to be bound to all VLANs (as identified by
the VLAN tag in tagged frames) received on this port. Consequently, ports are
bound to those VLANs that actually have members that are reachable through the
port.
❒ Manually creating a VLAN Switch Port in the VLAN Switch Ports dialog box.
Egress Rules
For a given port/VLAN combination, egress rules determine whether frames transmitted
from the port on the VLAN are tagged or untagged. This is accomplished by setting the
Trunking Mode attribute in the Switch Port Configuration dialog box.
For example, choosing the IEEE 802.1Q trunk mode causes all frames transmitted out of
the port to be tagged using the IEEE 802.1Q tag header format. Individual port/VLAN
combinations may be changed to cause frames transmitted from the port to be untagged
for particular VLANs.
Port-Based VLANs
VLAN assignment of a packet is based on global VLAN ID. Regardless of any name you
assign to a VLAN, the switch looks only at the VLAN ID number to determine a packet’s
VLAN destination.