Allied Telesis at-8516f User Guide
Layer 2 Switching
85
Software Release 2.6.1
C613-02025-00 REV C
C613-02025-00 REV C
the switch floods the frame on all ports in the VLAN except the port on which
the frame was received. If the destination address is found, the switch discards
the frame if the port is not in the STP ‘Forwarding’ state, if the destination
address is on the same port as the source address, or if there is a static filter
entry for the destination address set to DISCARD (“Layer 2 Filtering” on
page 85). Otherwise, the frame is forwarded on the indicated port.
the frame was received. If the destination address is found, the switch discards
the frame if the port is not in the STP ‘Forwarding’ state, if the destination
address is on the same port as the source address, or if there is a static filter
entry for the destination address set to DISCARD (“Layer 2 Filtering” on
page 85). Otherwise, the frame is forwarded on the indicated port.
This whole process can further be modified by the action of static switch filters.
These are configurable filters which allow switched frames to be checked
against a number of entries.
These are configurable filters which allow switched frames to be checked
against a number of entries.
The Forwarding Process provides storage for queued frames to be transmitted
over a particular port or ports. More than one transmission queue may be
provided for a given port. Which transmission queue a frame is sent to is
determined by the user priority tag in the Ethernet frame, and the Quality of
Service mapping.
over a particular port or ports. More than one transmission queue may be
provided for a given port. Which transmission queue a frame is sent to is
determined by the user priority tag in the Ethernet frame, and the Quality of
Service mapping.
Layer 2 Filtering
The switch has a Forwarding Database, entries in which 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 802.1D Standard “Media Access Control
(MAC) Bridges”.
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 802.1D Standard “Media Access Control
(MAC) Bridges”.
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.
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.
whether frames with given values of the destination MAC address field should
be forwarded to a given port.
To add or delete static switch filter entries, use the commands:
ADD SWITCH FILTER DESTADDRESS=macadd ACTION={FORWARD|DISCARD}
PORT[=port-list] [ENTRY=entry] [VLAN={vlanname|1..4094}]
DELETE SWITCH FILTER ENTRY=entry-list
The switch automatically deletes static filter entries for a port if the port is deleted from
the specified VLAN.
the specified VLAN.
To display current static switch filter entries, use the command:
SHOW SWITCH FILTER [DESTADDRESS=macadd] [ENTRY=entry]
[PORT=port-list] [VLAN={vlanname|1..4094}]