Specifications

Switching 8-31
Software Release 2.7.3
C613-03098-00 REV A
The Egress Rules
After the forwarding process determines the ports and transmission queues
from which a frame is forwarded, the Egress Rules for each port determine
whether the outgoing frame is VLAN-tagged with its numerical VLAN
Identifier (VID).
When you add a port to a VLAN, configure it to transmit either untagged or
VLAN tagged packets by using the command:
add vlan={vlan-name|1..4094} port={port-list|all}
[frame={tagged|untagged}]
To change this setting for a port that is already part of a VLAN, use the
command:
set vlan={vlan-name|1..4094} port={port-list|all}
frame={untagged|tagged}
Layer 2 Filtering
The switch has a forwarding database, entries that determine whether frames
are forwarded or discarded over each port. Entries in this forwarding database
are created dynamically by the learning process. A dynamic entry is
automatically deleted from the Forwarding Database when its ageing timer
expires. Filtering is specified in the IEEE Standard 802.1d.
The user can configure static switch filter entries using the command line
interface. Static switch filter entries associate a MAC address with a VLAN and
a port in the VLAN. When the switch receives a frame with a destination
address and VLAN Identifier that match those of a static filter entry, the frame
can be either forwarded to the port specified in the static filter entry, or
discarded.
The forwarding database supports queries by the forwarding process as to
whether frames with given values of the destination MAC address field should
be forwarded to a given port.
To add or delete a static switch filter entry, use the command:
add switch filter action={forward|discard} destaddress=macadd
port=port [entry=entry] [learn] [vlan={vlan-name|1..4094}]
delete switch filter port=port entry=entry-list
To display current static and learned switch filter entries, use the command:
show switch filter [port={port-list|all}]
[destaddress=macadd] [entry=entrylist] [vlan={vlan-name|
1..4094}]
For each VLAN, the destination MAC address of a frame to be forwarded is
checked against the forwarding database. If there is no entry for the destination
address and VLAN, the frame is transmitted on all ports in the VLAN that are
in the forwarding or disabled states, except the port on which the frame was
received. This process is referred to as flooding. If an entry is found in the
forwarding database, but the entry is not marked as forwarding or it points to
the same port the frame was received on, the frame is discarded. Otherwise,