Allied Telesis Rapier Switch - Manual (Page 38)

38 Rapier Switch Software Reference
Software Release 2.5.1
C613-02025-00 REV B
Addresses can be manually added to a port locked list up to a total of 256 MAC
addresses, and the learning limit can be extended to accommodate them, by
using the command:
ADD SWITCH FILTER ACTION={FORWARD|DISCARD} DESTADDRESS=macadd
PORT=port [ENTRY=entry] [LEARN] [VLAN={vlanname|1..4094}]
Learned addresses on locked ports can be saved as part of the switch
configuration, so that they will be part of the configuration after a power cycle,
using the command:
CREATE CONFIG=filename
If the configuration is not saved when there is a locked list for a port, the
learning process begins again after the router is restarted.
Virtual Local Area Networks (VLANs)
A Virtual LAN (VLAN) is a logical, software-defined subnetwork. It allows
similar devices on the network to be grouped together into one broadcast
domain, irrespective of their physical position in the network. Multiple VLANs
can be used to group workstations, servers, and other network equipment
connected to the switch, according to similar data and security requirements.
Decoupling logical broadcast domains from the physical wiring topology
offers several advantages, including the ability to:
■ Move devices and people with minimal, or no, reconfiguration
■ Change a device’s broadcast domain and access to resources without
physically moving the device, by software reconfiguration or by moving its
cable from one switch port to another
■ Isolate parts of the network from other parts, by placing them in different
VLANs
■ Share servers and other network resources without losing data isolation or
security
■ Direct broadcast traffic to only those devices which need to receive it, to
reduce traffic across the network
■ Connect 802.1Q-compatible switches together through one port on each
switch
Devices that are members of the same VLAN only exchange data with each
other through the switch’s switching capabilities. To exchange data between
devices in separate VLANs, the switch’s routing capabilities are used. The
switch passes VLAN status information, indicating whether a VLAN is up or
down, to the Internet Protocol (IP) module. IP uses this information to
determine route availability.
The switch has a maximum of 4094 VLANs, ranging from a VLAN identifier
(VID) of 1 to 4094. When the switch is first powered up, a “default” VLAN is
created and all ports are added to it. In this initial unconfigured state, the
switch will broadcast all the packets it receives to the default VLAN. This
VLAN has a VID of 1 and an interface name of vlan1. It cannot be deleted, and
ports can only be removed from it if they also belong to at least one other