Nortel Networks 1000ASE-XD - Manual (Page 178)

178 Chapter 4 Troubleshooting
209418-A
In both situations, the BayStack 420 Switch “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:
1 Use the Port Configuration screen to disable autonegotiation for the suspect
port (see
“Port Configuration screen” on page 129 ).
2 Manually set the Speed/Duplex field to match the speed/duplex mode of the
connected station (see
Table 24 on page 130 ).
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 BayStack 420 Switch port.
Port interface
Ensure that the devices are connected using the appropriate crossover or
straight-through cable (see
Appendix D, “Connectors and pin assignments,” on
page 195 ), or that autonegotiation or autopolarity is active.