User guide

46 AR400 Series User Guide
Software Release 2.4.1
C613-02021-00 REV B
Synchronous Ports
You can use the asynchronous console port on the base unit to configure the
router. Additional asynchronous ports can also connect terminals, printers and
terminal ports on host computers.
Your router supports synchronous interfaces with speeds of up to 2.048 Mbps,
also known as E1. The router will automatically generate a clock signal when a
DCE transition cable is connected to a synchronous interface (see the AR Series
Router Hardware Reference for details of how to construct a cable).
To set the clock speed, enter the command:
SET SYN=n SPEED=speed
For more information about synchronous interfaces, see the Interfaces chapter
in the AR400 Series Router Software Reference.
Switch Ports
A switch port is one of the physical Ethernet interfaces on the base router unit.
Each switch port is uniquely identified by a port number.
To display information about switch ports, enter the command:
SHOW SWITCH PORT[={port-list|ALL}]
All switch ports on the router are enabled by default. You can disable and
enable a switch port as required. To enable or disable a switch port, enter the
commands:
ENABLE SWITCH PORT={port-list|ALL}
DISABLE SWITCH PORT={port-list|ALL}
Port Speed and Duplex Mode
Each switch port can operate at either 10 Mbps or 100 Mbps, in either full
duplex or half duplex mode. In full duplex mode a port can transmit and
receive data simultaneously, while in half duplex mode the port can either
transmit or receive, but not at the same time. This versatility makes it possible
to connect devices with different speeds and duplex modes to different ports
on the router. Such versatility also requires that each port on the router know
which speed and mode to use. The ports can automatically adjust their speed
and duplex mode to accommodate the devices connected to them. This
adjustment is referred to as “autonegotiation”.
You have two options when you configure switch ports. Firstly, you can
configure each switch port with a fixed speed and duplex mode. Secondly, you
can configure each switch port to autonegotiate speed and duplex mode with a
device connected to it to determine a speed and mode that will allow
successful transmission. An autonegotiating port will adopt the speed and
duplex mode required by devices connected to it. If another autonegotiating
device is connected to the router, they will negotiate the highest possible
common speed and duplex mode (Table 8 on page 47). Setting the port to a
fixed speed and duplex mode allows it to support equipment that cannot
autonegotiate. When a port at one end of the link is set to a fixed speed (non-
autonegotiating) set the port at the other end of the link to operate at the same
speed. This is because when autonegotiation is disabled, the link partner is not