Link Failures; Determining A Successful Speed Negotiation - Brocade Communications Systems 1606 Troubleshooting Manual

3

Link failures

Link failures
A link failure occurs when a server, storage, or switch device is connected to a switch, but the link
between the devices does not come up. This prevents the devices from communicating to or
through the switch.
If the switchShow command or LEDs indicate that the link has not come up properly, use one or
more of the following procedures.
The port negotiates the link speed with the opposite side. The negotiation usually completes in one
or two seconds; however, sometimes the speed negotiation fails.

Determining a successful speed negotiation

NOTE
Skip this procedure if the port speed is set to a static speed through the portCfgSpeed command.
1. Enter the portCfgShow command to display the port speed settings of all the ports.
2. Enter the switchShow command to determine if the port has module light.
3. Enter the portCfgSpeed command to change the port speed to 1, 2, 4 or 8 Gbps, depending on
4. Enter the portLogShow or portLogDump command.
5. Check the events area of the output:
6. Correct the negotiation by entering the portCfgSpeed [slotnumber/]portnumber, speed_level
24
what speed can be used by both devices. This should correct the negotiation by setting to one
speed.
time task
-----------------------------------------------------------------
14:38:51.976 SPEE
14:39:39.227 SPEE
•
In the column sn indicates a speed negotiation.
event
•
In the column NC indicates the negotiation has completed.
cmd
If these fields do not appear, proceed to the
command if the fields in step 5
switch:admin> portcfgspeed
Usage: portCfgSpeed PortNumber
Speed_Level: 0 - Auto Negotiate
1 - 1Gbps
2 - 2Gbps
4 - 4Gbps
8 - 8Gbps
ax - Auto Negotiate + enhanced retries
event port cmd
sn <Port#> NC
sn <Port#> NC
step 6.
do not appear.
Speed_Level
Fabric OS Troubleshoot and Diagnostics Guide
args
00000001,00000000,00000001
00000002,00000000,00000001
53-1001340-01