Cisco Catalyst Switch Compatibility and Operation−Specific Issues
These sections deal with specific Cisco Catalyst switch issues that can affect performance, compatibility, and interoperation of certain NICs.
Catalyst 8510 and 8540 CSR
In the campus switch router (CSR) Cisco IOS Software Release 12.0(5)W5(13), autonegotiation for speed and duplex are enabled by default. In earlier releases, autonegotiation is not supported by default. As a result, each connected interface must be set to run in full−duplex mode. If you upgrade to Cisco IOS Software Release 12.0(5)W5(13) with a router that runs in manually full−duplex mode, you experience performance issues. The symptoms include high collision rate, reduced throughput, and more packet drops. This is because the Catalyst 8500 waits to autonegotiate with the connected device. Now that the connected device is forced to run in full−duplex mode, it does not participate in autonegotiation. Based on the specification, this causes the Catalyst 8500 interface to settle in half−duplex mode, which causes a mismatch between the device and the Catalyst 8500 at the interface level. Catalyst 8500 interface defaults to half−duplex mode when the peer is incapable of negotiation.
Catalyst 6000 and 6500 Switches
This table describes Cisco bug IDs found on the Catalyst 6000 and 6500 switches.
Table 7
Cisco Bug ID | Resolved | Description |
| In | |
|
| |
|
| When a port goes into the |
|
| errdisable state on a Catalyst |
|
| 6000 or 6500, the switch |
|
| inadvertently learns the MAC |
CSCdm48887 |
| addresses of other devices to be |
( registered |
| learned from the errdisable |
customers only) | 5.2.3, | port. The errdisable state is |
| 5.3.1a | caused by excessive late collisions |
|
| on a port. Since all traffic on that |
|
| VLAN is forwarded incorrectly out |
|
| of the incorrect port, there is a loss |
|
| of connectivity. This errdisable |
|
| state can appear as a result of a |
|
| duplex mismatch or faulty NIC. |
|
|
|
CSCdm80035 |
| When a Gigabit connection is reset |
( registered |
| on a Catalyst 6000 or 6500, the |
customers only) | 5.2.3, | connection can potentially not |
| 5.3.1a | reconnect. A symptom of this issue |
|
| can be that a Gigabit NIC does not |
|
| connect after reset or disconnect. |
|
|
|
CSCdm88013 | 5.2.3, | Occasionally, host NICs connected |
( registered | 5.3.1a | to WS−X6248−TEL or |
customers only) |
| WS−X6248−RJ−45 modules can |
|
| incorrectly revert to half−duplex |
|
|
|
