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Cisco Catalyst 6000 Series Switches

Field Notice: *Expired* FN - 21813 - Inconsistency Between OS CEF Adjacency Table and Hardware CEF Adjacency Table in CatOS


Revised April 18, 2008

November 11, 2002


NOTICE:

THIS FIELD NOTICE HAS BEEN EXPIRED AND IS NO LONGER MAINTAINED OR UPDATED BY CISCO.

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE, WARRANTY OR SUPPORT. USE OF THE INFORMATION ON THIS FIELD NOTICE OR MATERIALS LINKED FROM THIS FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.

Products Affected

Product

Comments

CatOS versions 6.3(8), 6.3(9), 7.3(2)

Supervisor 2 images when used with an MSFC2.

  

Problem Description

Due to a fix for CSCdx88297 (registered customers only) , a new caveat has been introduced that can cause the hardware FIB install and delete messages, which are sent from the MSFC2 to the switch, to be ignored by the switch. This results in an inconsistency between the FIB tables on the Supervisor 2 and the MSFC2. Catalyst 6000 systems with Supervisor 2 and MSFC2 running CatOS versions 6.3(8), 6.3(9) or 7.3(2) are affected by this caveat.

Background

The Supervisor 2/MSFC2 introduced a feature that monitors certain counters on the out-of-band management interface. When those counters don't change, the out-of-band management interface is re-initialized. After this re-initialization, certain internal entries need to be re-installed. They are not installed properly thereby causing some messages from the MSFC2 to the Supervisor 2 to be ignored.

Problem Symptoms

The MSFC2 on a Supervisor 2 may have the IOS CEF and adjacency tables correctly populated, but these may not be updated in the hardware table on the switch. To verify if this is an issue, validate the IOS CEF table and the switch CEF table to look for any inconsistencies.

To determine if the switch is affected, add a static route for a non-existent route on the MSFC2, then verify that the route is populated in the CEF table on both the MSFC2 and the switch. An example is shown below:

The MSFC2

msfc2(config)#ip route 1.1.1.0 255.255.255.0 null0
msfc2#show ip cef 1.1.1.0
1.1.1.0/24, version 15, attached
0 packets, 0 bytes
  via Null0, 0 dependencies
    valid null adjacency

The Switch

6509 (enable) show mls entry cef ip 1.1.1.0/24
Mod FIB-Type  Destination-IP  Destination-Mask NextHop-IP      Weight
--- --------- --------------- ---------------- --------------- ------ 
15 resolved  1.1.1.0         255.255.255.0    0.0.0.0              1

For details on the commands used to check the IOS CEF table and Switch CEF table reference, see Configuring CEF for PFC2. For troubleshooting assistance, see How-To Troubleshoot Unicast IP Routing CEF on Catalyst 6000s with a Supervisor 2 in Hybrid Mode.

This issue has been fixed in CSCdy75968 (registered customers only) .

Workaround/Solution

The workaround is to downgrade to an older version CatOS not affected by this DDTS. The solution for this issue will be to upgrade to versions 6.3(10) or 7.4(2) once they are available. Further details can be found in the DDTS referenced below.

DDTS

To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.

DDTS

Description

CSCdy75968 (registered customers only)

Inconsistency between IOS CEF / Adj table and HW CEF /Adj table

  

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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