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Cisco IOS Software Releases 11.2

Field Notice: *Expired* Cisco IOS Software Releases 11.2(10a), 11.2(10a)BC, 11.2(10a)P, 11.2(10a)P1 and Current EIGRP Defects


Revised August 23, 2007

December 24, 1997

NOTICE:

THIS FIELD NOTICE HAS BEEN ARCHIVED AND IS NO LONGER MAINTAINED OR UPDATED BY CISCO.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


Description

This notice describes Cisco IOS Software Releases 11.2(10a), 11.2(10a)BC, 11.2(10a)P and 11.2(10a)P1 and explains why these releases were created. This notice also describes EIGRP redistribution defects that still affect these releases.

Cisco Systems, Inc. strives to maintain the highest software quality standards in the internetworking industry. We also seek to provide you, our customers and partners, with the most thorough and advanced software quality information as part of the services available under your Cisco service agreement.

Products Affected

Software Release

Images Affected

11.2(10a)

All images

11.2(10a)BC

All images

11.2(10a)P

All images

11.2(10a)P1

c5200 and c5300 images only

Problem Description

Unexpected ARP and EIGRP behaviors, caused by defects CSCdj60533 and CSCdj58676 respectively, were deemed serious enough to warrant rebuilds of releases 11.2(10), 11.2(10)BC, and 11.2(10)P. The rebuilt releases, which include fixes for these defects, are named 11.2(10a), 11.2(10a)BC, and 11.2(10a)P. A small number of critical fixes for other issues were also applied to 11.2(10a)BC and 11.2(10a)P.

The fix that was committed for CSCdj58676 resolved some EIGRP problems, but created the symptoms described by CSCdj65737. These symptoms are present in releases 11.2(10a), 11.2(10a)BC, and 11.2(10a)P. Customers using EIGRP and redistribution should review their configurations and determine if this defect applies to them.

Release 11.2(10a)P1 was created to correct CSCdj65737 and a defect which affected only the AS5200 and AS5300 platforms (CSCdj22528). This release was created specifically for the initial shipments of the next phase of Cisco's Access Path product, which includes the AS5300 platform.

Fixes Integrated in Each Release

11.2(10a) Bugfixes

  • CSCdj58676 - EIGRP Redistribution doesn't work when interface flaps.

  • CSCdj60533 - Back out CSCdj39289, which causes invalid suspend in ARP lookup.

11.2(10a)BC Bugfixes

  • CSCdj58676 - EIGRP redistribution doesn't work when interface flaps.

  • CSCdj60533 - Back out CSCdj39289, which causes invalid suspend in ARP lookup.

  • CSCdj60903 - 11.2(10)BC object files for appn subsystem.

  • CSCdj62649 - A problem with SNMP getnext support for TN3270s nailing table

11.2(10a)P Bugfixes

  • CSCdj58676 - EIGRP Redistribution doesn't work when interface flaps.

  • CSCdj60533 - Back out CSCdj39289, which causes invalid suspend in ARP lookup.

  • CSCdj44456 - An AS5300 system with Microcom and Mica modems can crash if fastring is disabled.

  • CSCdj54177 - Missing support for the modem country feature.

  • CSCdj59360 - VIP ipc_dispatch process is calling malloc (at interrupt level), which causes a crash.

11.2(10a)P1 Bugfixes

  • CSCdj22528 - EIGRP hello updates are being sent out the virtual access interfaces, even though the offload configuration specifies the Virtual-Template interface as being passive.

  • CSCdj65737 - Dynamic redistribution into EIGRP from another routing protocol fails if the routes being redistributed fall within the same major network as EIGRP.

Description of IP Protocols Defect CSCdj60533

The ARP lookup routine may suspend, causing unexpected behaviors for IP protocols. For example: If the OSPF routing process is traversing a list of neighbors to send LSA packets and the ARP routine is called, the ARP routine suspension could cause a system reset.

This defect was introduced by code changes associated with CSCdj39289. The change made by CSCdj60533 is to back out the code committed by CSCdj39289, therefore the behavior reported in CSCdj39289 may still occur. That behavior is that packets generated by the router itself (such as syslog) may be dropped while ARP lookup takes place.

Description of EIGRP Defect CSCdj58676

This defect affects redistribution of routes into the EIGRP routing process. The following types of routes may not be correctly redistributed:

  • A directly connected route

  • A static route with the next hop set to an interface

  • A static route with the next hop set to a dynamically learned route

The defect becomes apparent only after a dynamic event, therefore when redistribution is initially configured, EIGRP will reflect correct information in the topology table, however after any sort of dynamic event (such as an interface changing state) the topology table is no longer valid and routing updates sent will be inaccurate.

Description of EIGRP Redistribution Defect CSCdj65737

This defect was introduced by code changes associated with CSCdj58676. The issue is that routes are not being redistributed into EIGRP from other routing protocols if both protocols are routing for the same major network.

The code changes for CSCdj58676 were only applied to 11.2(10a), 11.2(10a)BC and 11.2(10a)P releases, therefore, those releases are the only ones impacted by CSCdj65737. The fix to CSCdj65737 will be to back out the code changes committed by CSCdj58676 and CSCdj28874. That change will have the effect of re-introducing the behavior reported by CSCdj28874.

Description of EIGRP Redistribution Defect CSCdj28874

When a network is included in the EIGRP routing process because it is specified with the network x.x.x.x command and that same network is redistributed into EIGRP via the redistribute connected command, there will be two entries for the network in the EIGRP topology table.

If the interface connecting that network goes down, only one of the two entries will be removed from the topology table. The entry learned via redistribution will remain in the topology table and be advertised, even though it is no longer valid.

If you are a registered CCO user and you have logged in, you can view bug details.

Details

View bug details for the following:

  • CSCdj60533 (registered customers only) - Back out CSCdj39289, which causes invalid suspend in ARP lookup.

  • CSCdj39289 (registered customers only) - Self-generated packet wrongly dropped when sending ARP request.

  • CSCdj58676 (registered customers only) - EIGRP redistribution doesn't work when interface flaps.

  • CSCdj65737 (registered customers only) - Redistribution into EIGRP fails if protocol routing into same major network as EIGRP.

  • CSCdj28874 (registered customers only) - EIGRP topology entry from redistribute connected does not clear.

  • CSCdj58853 (registered customers only) - EIGRP summary routes are not being propagated.

Workaround/Solution

A workaround for both CSCdj60533 and CSCdi39289 is to configure static ARP cache entries for devices on LAN segments with the router until a new software version containing the fix is released. This approach may not be viable for segments with many hosts, however, for backbone or DMZ/firewall segments with few hosts and routers, this is recommended. It is also possible to decrease the possibility of problem occurrence by increasing the timeout value for ARP cache entries. The default timeout interval is four hours.

The code back-outs of CSCdj65737 and re-introduction of CSCdj28874 will appear in the following releases:

  • 11.2: 11.2(11), 11.2(11)BC, 11.2(11)P

  • 11.1: 11.1(16), 11.1(16)AA, 11.1(16)CA, 11.1(16)IA

The symptoms of CSCdj28874 may be avoided by not using the redistributed connected command and instead specifying the individual networks to be redistributed into EIGRP.

Background

Defect CSCdj65737 only affects networks running the EIGRP routing protocol and using route redistribution. The changes made by CSCdj65737 will be removing code committed by CSCdj28874 and CSCdj58676, thereby reverting back to the less serious behavior described by CSCdj28874.

Defect CSCdj68388 has been assigned to address the reintroduced behavior originally described by CSCdj28874. CSCdj68388 will be resolved in a future release in early 1998.

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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