User guide
E
XTREME
W
ARE
S
OFTWARE
U
SER
G
UIDE
B-5
U
SING
THE
C
OMMAND
-L
INE
I
NTERFACE
In the case where no one knows a password for an administrator level user, contact
your supplier.
P
ORT
C
ONFIGURATION
No link light on 10/100 Base port:
If patching from a hub or switch to another hub or switch, ensure that you are using a
CAT5 cross-over cable. This is a CAT5 cable that has pins 1&2 on one end connected to
pins 3&6 on the other end.
Excessive RX CRC errors:
When a device that has auto-negotiation disabled is connected to a Extreme switch that
has auto-negotiation enabled, the Extreme switch links at the correct speed, but in half
duplex mode. The Extreme switch 10/100 physical interface uses a method called
parallel detection to bring up the link. Because the other network device is not
participating in auto-negotiation (and does not advertise its capabilities), parallel
detection on the Extreme switch is only able to sense 10Mbps versus 100Mbps speed,
and not the duplex mode. Therefore, the switch establishes the link in half duplex mode
using the correct speed.
The only way to establish a full duplex link is to either force it at both sides, or run
auto-negotiation on both sides (using full duplex as an advertised capability, which is
the default setting on the Extreme switch).
A mismatch of duplex mode between the Extreme switch and another network
device will cause poor network performance. Viewing statistics using the
show
port rx
command on the Extreme switch may display a constant increment of
CRC errors. This is characteristic of a duplex mismatch between devices. This is
NOT a problem with the Extreme switch.
Always verify that the Extreme switch and the network device match in configuration
for speed and duplex.
No link light on Gigabit fiber port:
Check to ensure that the transmit fiber goes to the receive fiber side of the other device,
and vice-versa. All gigabit fiber cables are of the cross-over type.
The Extreme switch has auto-negotiation set to on by default for gigabit ports. These
ports need to be set to auto off (using the command
config port <port #> auto
off
) if you are connecting it to devices that do not support auto-negotiation.