340
Troubleshooting
The Ethernet Routing Switch 2500 Series negotiates port speeds
according to the IEEE 802.3u autonegotiating standard. The switch adjusts
(autonegotiates) its port speed and duplex mode to match the best service
provided by the connected station, up to 100 Mb/s in full-duplex mode as
follows:
•
If the connected station uses a form of autonegotiation that is not
compatible with the IEEE 802.3u autonegotiating standard, the Ethernet
Routing Switch 2500 Series cannot negotiate a compatible mode for
correct operation.
•
If the autonegotiation feature is not present or not enabled at the
connected station, the Ethernet Routing Switch 2500 Series may not be
able to determine the correct duplex modes.
In both situations, the Ethernet Routing Switch 2500 Series "autosenses"
the speed of the connected station and, by default, reverts to half-duplex
mode. If the connected station is operating in full-duplex mode, it cannot
communicate with the switch.
To correct this mode mismatch problem, use the following procedure:
1. Use the Port Management page to disable autonegotiation for the
suspect port (see
"Configuring switch port status" (page 324)
).
2. Manually set the Speed/Duplex field to match the speed/duplex mode
of the connected station.
You may have to try several settings before you find the correct
speed/duplex mode of the connected station.
If the problem persists:
1. Disable the autonegotiation feature at the connected station.
2. Manually set the speed/duplex mode of the connected station to the
same speed/duplex mode you have manually set for the Ethernet
Routing Switch 2500 Series port.
Port interface
Ensure that the devices are connected using the appropriate crossover or
straight-through cable, or that autonegotiation is active.
Nortel Ethernet Routing Switch 2500 Series
Overview — System Configuration
NN47215-500 (323162-B)
02.02
Standard
4.1
19 November 2007
Copyright © 2007, Nortel Networks
.
