Install guide

34 Release Note
Rapier Switch Software Release 2.1.0
C613-10200-01 Rev A
untagged frames admitted by the ACCEPTABLE parameter are admitted, since
they have the VID of the VLAN for which the port in an untagged member. If
OFF is specified, Ingress Filtering is disabled, and no frames are discarded by
this part of the Ingress Rules. The default setting is OFF.
To display the current Ingress Rules (Figure 8 on page 19), use the command:
SHOW SWITCH PORT=port-list
The Learning Process
The Learning Process uses an adaptive learning algorithm, sometimes called
backward learning to discover the location of each station on the extended LAN.
All frames admitted by the Ingress Rules on any port are passed on to the
Forwarding Process if they are for destinations within the same VLAN. Frames
destined for other VLANs are passed to the Layer 3 protocol, for instance IP.
For every frame admitted, the frame’s source MAC address and VID are
compared with entries in a Forwarding Database for the VLAN (also known as
a MAC address table, or a forwarding table) maintained by the switch. The
Forwarding Database contains one entry for every unique station MAC
address the switch knows in each VLAN.
If the frame’s source address is not already in the Forwarding Database for the
VLAN, the address is added and an ageing timer for that entry is started. If the
frame’s source address is already in the Forwarding Database, the ageing timer
for that entry is restarted. By default, switch learning is enabled, and it can be
disabled or enabled using the commands:
DISABLE SWITCH LEARNING
ENABLE SWITCH LEARNING
If the ageing timer for an entry in the Forwarding Database expires before
another frame with the same source address is received, the entry is removed
from the Forwarding Database. This prevents the Forwarding Database from
being filled up with information about stations that are inactive or have been
disconnected from the network, while ensuring that entries for active stations
are kept alive in the Forwarding Database. By default, the ageing timer is
enabled, and it can be disabled or enabled using the commands:
ENABLE SWITCH AGEINGTIMER
DISABLE SWITCH AGEINGTIMER
The default value of the ageing timer is 300 seconds (5 minutes), and this can
be modified using the command:
SET SWITCH AGEINGTIMER=10..1000000
The Forwarding Database relates a station’s (source) address to a port on the
switch, and is used by the switch to determine from which port (if any) to
transmit frames with a destination MAC address matching the entry in the
station map.
The Forwarding Process
The Forwarding Process forwards received frames that are to be relayed to
other ports in the same VLAN, filtering out frames on the basis of information
contained in the station map and on the state of the ports. If a frame is received
on the port for a destination in a different VLAN, it is either Layer 3 switched if
it is an IP packet, or looked up in the Layer 3 routing tables (see the AR Series
Router Reference Manual at http://www.alliedtelesyn.co.nz/support/rapier/
.)