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Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
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Chapter47 Troubleshooting Preventing Autonegotiation Mismatches
Removing powered-on stack members causes the switch stack to divide (partition) into two or more
switch stacks, each with the same configuration. If you want the switch stack s to remain separa te, change
the IP address or addresses of the newly created switch stacks. To recover from a partitioned switch
stack:
1. Power off the newly created switch stacks.
2. Reconnect them to the original switch stack through their StackWise Plus ports.
3. Power on the switches.
For the commands that you can use to monitor the switch stack and its members, see the “Displaying
Switch Stack Information” section on page 5-25.
Preventing Autonegotiation Mismatches
The IEEE 802.3ab autonegotiation protocol manages the switch settings for spee d (10 Mb/s, 100 Mb/s,
and 1000 Mb/s, excluding SFP module ports) and duplex (half or full). There are situations when this
protocol can incorrectly align these settings, reducing per forma nc e. A mi sm atc h oc cu rs u nder th ese
circumstances:
•A manually set speed or duplex parameter is different from the manually set speed or duplex
parameter on the connected port.
•A port is set to autonegotiate, and the connected port is set to full duplex with no autonegotiation.
To maximize switch performance and ensure a link, follow one of these guidelines when changing the
settings for duplex and speed:
•Let both ports autonegotiate both speed and duplex.
•Manually set the speed and duplex parameters for the ports on both ends of the connection.
Note If a remote device does not autonegotiate, configure the duplex settings on the two por ts to ma tc h. The
speed parameter can adjust itself even if the connected port does not autonegotiate.
SFP Module Security and Identification
Cisco small form-factor pluggable (SFP) modules have a serial EEPROM that contains the module serial
number, the vendor name and ID, a unique security code, and cyclic redundancy check (CRC). When an
SFP module is inserted in the switch, the switch software reads the EEPROM to verify the serial number,
vendor name and vendor ID, and recompute the security code and CRC. If the serial number, the vendor
name or vendor ID, the security code, or CRC is invalid, the software generates a se curity error messa ge
and places the interface in an error-disabled state.
Note The security error message references the GBIC_SECURITY facility. The switch supports SFP modules
and does not support GBIC modules. Although the error message text re fers t o GB IC int erfaces an d
modules, the security messages actually refer to the SFP modules and module interfaces. For more
information about error messages, see the system messag e gui de for thi s rel ease .
If you are using a non-Cisco SFP module, remove the SFP module from the switch, and replace it with
a Cisco module. After inserting a Cisco SFP module, use the errdisable recovery cause gbic-invalid
global configuration command to verify the port status, and enter a time interval for recoverin g from the