Release Notes for the Cisco 4000 Series for Cisco IOS Release 11.2

January 19, 1998

These release notes discuss the new features and significant software components for the Cisco 4000 series for Cisco IOS Release 11.2, up to and including 11.2(11).

For more detailed information about the features and caveats in these release notes, refer to the Release Notes for Cisco IOS Release 11.2, which contains features and caveats for all 11.2 platforms. The electronic documentation can be found on Cisco Connection Online (CCO) and on the Documentation CD-ROM. (Refer to the "Online Navigation" section for more details.)

Introduction

These release notes discuss the following topics:

• Determining Your Cisco IOS Software Release, page 2

• Cisco 4000 Series Routers, page 2

• Interfaces Supported on the Cisco 4000 Series, page 3

• Related Documentation, page 4

• Online Navigation, page 6

• New Features in Release 11.2(11) for the Cisco 4000 Series, page 6

• Cisco IOS Feature Sets for the Cisco 4000 Series, page 7

• Memory Requirements, page 13

• Upgrading to a New Software Release, page 15

• Caveats for Release 11.2(1) Through 11.2(11), page 15

• Caveats for Previous Releases, page 27

• Cisco Connection Online, page 28

• Documentation CD-ROM, page 29

Determining Your Cisco IOS Software Release

To determine which version of Cisco IOS software is running on your Cisco 4000 series router, log in to the router and enter the show version User EXEC command, as shown below:

router> show version
Cisco Internetwork Operating System Software
IOS (tm) 4500 Software (C4500-J-M), Version 11.2, SHARED PLATFORM,
RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1998 by cisco Systems, Inc.
Compiled Tue 11-Feb-97 19:32 by tamb
Image text-base: 0x600088A0, data-base: 0x607A4000
ROM: System Bootstrap, Version 5.3(10) [tamb 10], RELEASE SOFTWARE (fc1)
ROM: 4500 Bootstrap Software (C4500-BOOT-M), Version 10.3(1), RELEASE
SOFTWARE (fc1)
4700 uptime is 2 minutes
System restarted by reload
System image file is "flash:c4500-j-mz.112-4.P", booted via flash
cisco 4700 (R4K) processor (revision D) with 16384K/4096K bytes of memory.
Processor board ID 03755623
R4700 processor, Implementation 33, Revision 1.0 (Level 2 Cache)
G.703/E1 software, Version 1.0.
Bridging software.
SuperLAT software copyright 1990 by Meridian Technology Corp).
X.25 software, Version 2.0, NET2, BFE and GOSIP compliant.
TN3270 Emulation software (copyright 1994 by TGV Inc).
6 Ethernet/IEEE 802.3 interface(s)
2 Token Ring/IEEE 802.5 interface(s)
2 Serial network interface(s)
4294967294 terminal line(s)
128K bytes of non-volatile configuration memory.
4096K bytes of processor board System flash (Read/Write)
4096K bytes of processor board Boot flash (Read/Write)
Configuration register is 0x0

Cisco 4000 Series Routers

The following Cisco 4000 series routers are supported by Cisco IOS Release 11.2(11):

• Cisco 4000, Cisco 4000-M

• Cisco 4500, Cisco 4500-M

• Cisco 4700, Cisco 4700-M

Interfaces Supported on the Cisco 4000 Series

This section identifies the LAN and WAN interfaces supported on Cisco 4000 series routers.

The following LAN interfaces are supported on Cisco 4000 series routers:

• Ethernet (AUI)

• Ethernet (10BaseT)

• Ethernet (10BaseFL)

• Fast Ethernet (100BaseTX)

• Fast Ethernet (100BaseFX)

• 4-Mbps Token Ring

• 16-Mbps Token Ring

• FDDI DAS

• FDDI SAS

• FDDI multimode (DAS/SAS)

• FDDI single-mode

• ATM Interface

• MultiChannel Interface (Channelized E1/T1)

The following WAN data rates are supported on Cisco 4000 series routers:

• 48/56/64 kbps

• 1.544/2.048 Mbps

The following WAN interfaces are supported on Cisco 4000 series routers:

• EIA/TIA-232

• X.21

• V.35

• EIA/TIA-449

• EIA-530

• EIA/TIA-613 (HSSI)

• ISDN BRI

• ISDN PRI

• E1-G.703/G.704

• 56K/64K DSU/CSU

• Channelized T1

• Channelized E1

• Serial

Related Documentation

The Cisco IOS software documentation for Cisco IOS Release 11.2 is divided into eight modules. There are also four supporting documents.

Each documentation module consists of two books: a configuration guide and a corresponding command reference. Chapters in a configuration guide describe protocols, configuration tasks, and Cisco IOS software functionality and contain comprehensive configuration examples. Chapters in a command reference provide complete command syntax information. Each configuration guide can be used in conjunction with its corresponding command reference.

The Cisco IOS documentation set consists of the following books and chapter topics:

Online Navigation

The Cisco IOS software documentation set is available as printed manuals or electronic documents.

You can access the electronic documents either on Cisco Connection Online (CCO) on the World Wide Web or on the Cisco Documentation CD-ROM.

On CCO, go to Software and Support and select Documentation. Next, select Documentation, click on Cisco IOS Software Configuration, and then select Cisco IOS Release 11.2.

On the Documentation CD-ROM, go to Cisco Product Documentation, select Cisco IOS Software Configuration, and then select Cisco IOS Release 11.2.

Online documentation for Release 11.2 includes:

• Release Notes

• Feature Guides

• Configuration Guides and Command References

• Command Summary

• System Error Messages

• MIB User Quick Reference

• Debug Command Reference

• Access Services Quick Configuration Guide

• Caveats

For additional information about CCO and the Documentation CD-ROM, refer to the sections "Cisco Connection Online" and "Documentation CD-ROM" at the end of these release notes.

New Features in Release 11.2(11) for the Cisco 4000 Series

There are no new features applicable to the Cisco 4000 series in Cisco IOS Release 11.2(11).

Previous releases support features in the following categories:

• IBM Support

• Internet

• LAN Support

• Management

• Multimedia

• Quality of Service

• Security

• Switching

• Terminal Services

• WAN Optimization

• WAN Services

Detailed descriptions of the features can be found on CCO or on the Documentation CD-ROM. See the previous section "Online Navigation" for details.

Cisco IOS Feature Sets for the Cisco 4000 Series

The Cisco IOS software is packaged into "feature sets" (also called "software images"). There are many different feature sets available, and each feature set contains a specific subset of Cisco IOS features. The feature set matrix is used to see the overall feature set organization.

Feature Set Matrix

The feature set matrix (see Table 1) shows the new feature set organization and lists which feature sets are available on the Cisco 4000 series for Cisco IOS Release 11.2(11). The matrix uses the following symbols:

Cisco IOS images with strong encryption (including, but not limited to 56-bit DES) are subject to U.S. Government export controls, and have a limited distribution. Images to be installed outside the U.S. require an export license. Customer orders might be denied or subject to delay due to U.S. Government regulations. Contact your sales representative or distributor for more information, or send e-mail to export@cisco.com.

Feature Set Table

To determine what features are available with each feature set, see Table 2. The table summarizes what features you can use when running a specific feature set on the Cisco 4000 series for Cisco IOS Release 11.2(11). The feature set table uses the following symbols:

Memory Requirements

Table 3 describes the memory requirements for the Cisco 4000 series platform's feature set supported by Cisco IOS Release 11.2(11).

Beginning with Cisco IOS Release 10.3, some software image sizes exceed 4 MB and, when compressed, exceed 2 MB. Also, some systems now require more than 1 MB of main system memory for data structure tables.

For Cisco routers to take advantage of the Release 11.2 features, you must upgrade the code or main system memory as listed in Table 3. Some platforms have specific chip or architecture requirements that affect what can be upgraded and in what increments.

Upgrading to a New Software Release

For information on upgrading to a new software release, refer to the Cisco IOS Software Release Upgrade Paths and Packaging Simplification Product Bulletin #539.

You can access this product bulletin on the Web at http://www.cisco.com, http://www-europe.cisco.com, or http://www-china.cisco.com, or on the Documentation CD-ROM.

The path is as follows:

Cisco Connection Online: Products and Ordering: More Information: Product Bulletins: Cisco IOS Release 11.2: Cisco IOS Software Release 11.2 Changes in Packaging and Upgrade Paths (#539: 10/96)

Caveats for Release 11.2(1) Through 11.2(11)

This section describes possibly unexpected behavior by Release 11.2(11). Unless otherwise noted, these caveats apply to all 11.2 releases, up to and including 11.2(11).

AppleTalk

• The system might unexpectedly stop sending AARP request packets. Turning on AARP gleaning might help alleviate the problem. [CSCdi41414]

• The Catalyst 5000 RSM with only 16 MB of RAM might experience a system reload at initialization if running the -jsv image. The workaround is to add more memory. [CSCdj63501]

Basic System Services

• On RSP interfaces, optimum switching is supposed to be the default. However, depending on the link order of the image, it can default to off. [CSCdi54567]

• If you see the message "%RSP-3-RESTART: interface Serial x/y, output stuck" on an RSP-based platform, you might have problems with the output interfaces. This problem can occur when bursty traffic is optimum-switched to an output interface on which either fair queue or transmit-buffers backing-store is enabled. A possible workaround is to disable optimum switching. [CSCdi56782]

• The router might reload when trying to process the show accounting command. [CSCdi69364]

• In certain cases, the number of packets shown in the IP flow cache packet size distribution does not match the number shown in the cache statistics. [CSCdi71766]

• The show stacks command fails to report the correct version of code running at the time of the last reload. This problem occurs when the Flash memory version of the Cisco IOS software does not match the running version of code. [CSCdi74380]

• Fast switching and optimum switching counters should be broken out separately in the output of the show interface switching command. [CSCdi87008]

• A timing window within ccp_up could cause the router to crash if a packet gets sent to the hardware or distributed compressor while CCP is coming up. [CSCdj12504]

• Under heavy interrupt load, driver instrumentation gets hit repeatedly while processes are accessing the instrumentation variables (for example, last output time). This causes a number of problems, including stuck output and incorrect user displays. There is no known workaround. [CSCdj15583]

• A router configured with the ip identd and with aaa authentication login default tacacs+ enable commands reloads itself under these conditions:

  • The router is resolving host names via an external DNS server.

  • The TACACS server is down.

  • The user gains access to the router via the backup "enable" method.

  • The user attempts to Telnet from the router to a host on the network. After the Telnet is initiated, the router immediately reloads.

The workaround for this problem is to not configure the ip identd command or to disable the identd process with the global command no ip identd (which is the default). [CSCdj19961]

• A recovery mechanism for misaligned 64-bit accesses has been added. This new functionality is similar to the current misaligned handler for shorter misaligned accesses. [CSCdj20738]

• The tacacs-server directed-request restricted command applies only to authentication, not to accounting or authorization. Therefore, there is no way to restrict a user's authorization or accounting to a given set of servers, which can lead to inconsistencies. For example, authentication for a directed user can be attempted only on the restricted servers, whereas authorization or accounting can be attempted on nonrestricted servers as well. This inconsistency can cause authentication to pass while authorization fails for a given user. [CSCdj37496]

• In rare cases, an error might occur in Cisco routers. It might be seen as an error message describing an inconsistent state in allocating or deallocating blocks of memory.

An error was introduced by CSCdj42505 in Release 11.2 P and CSCdj22736 in Release 11.1CC. It does not exist in other Cisco IOS releases. [CSCdj44667]

• An SNMP trap process can cause high CPU utilization. The workaround is to remove SNMP. [CSCdj63629]

• The patch added in CSCdi37706 and incorporated into Cisco IOS Releases 11.2(8.1), 11.2(8.1)P, 11.3(0.2) and 11.2(8.1)BC was intended to correct a cosmetic problem with command authorization.

Instead, it exposed a bug in older implementations of the developers kit TACACS+ daemon (freeware) and will cause certain command authorizations to fail.

All freeware daemon versions prior to version 3.0.13 are subject to this problem including the ACE Safeword Security Server daemon. CiscoSecure daemons are not affected. [CSCdj66657]

• ARAP (ARA 2.1 & 3.0 client) with single line password using TACACS+ does not work.

To use the single line option, specify username*password in the username field and arap (lower case) in the password field.

The ARA 2.1 client returns the error "The connection attempt has failed. The server you called is not a valid Remote Access."

The ARA 3.0 client returns the error "User authentication failed. Check your user name and password and try again." [CSCdj68015]

EXEC and Configuration Parser

When the encapsulation is changed on an interface from one that supports weighted fair queueing to one that does not, and the change is made from the console or auxiliary port, there might be an 8-Kb memory loss each time the encapsulation is changed. To identify this problem, examine the output of the show memory allocating-process command, which shows that the number of memory blocks allocated by the EXEC increases each time you change the encapsulation. If you do not change the encapsulation on an interface often, this problem should not have a significant impact on system performance. [CSCdi89723]

IBM Connectivity

• Low-end platforms cache invalid RIF entries when using any form of the multiring command. This problem can also be seen in the DLSw reachability cache and with possible loops with LNM. [CSCdi50344]

• RSRB does not declare the peer dead until the keepalive times out. In order for RSRB to detect the dead peer so that the ring list can be cleaned up properly, set the keepalive value as small as possible. [CSCdi50513]

• Removing a DLSw configuration by configuring no dlsw local-peer and adding the DLSw configuration back can cause a memory leak in the middle buffer. [CSCdi51479]

• In some mixed-vendor bridge environments, Automatic Spanning Tree (AST) might not become active if the Cisco platform is the root bridge. The message-age-increment option is now available as part of the source-bridge spanning command to assist with the message-age count manipulation. This hidden command might be needed when the existing MAXAGE value is insufficient for network diameter and the maximum age is not configurable by the vendor bridges. [CSCdi53651]

• The LAN Network Manager (LNM) fails to link to the router's source bridge after the Token Ring interface is shut down on the remote router. The show lnm bridge command continues to display "Active Link" to the LNM. This problem does not occur when bridges are linked locally to the LNM. The workaround is to remove the source-bridge command from the Token Ring interface and configure it back in. [CSCdi53954]

• When the router is configured to use the DSPU feature, it might crash during deactivation of multiple downstream physical units (PUs). [CSCdi54114]

• A router might crash when DSPU debugging is enabled on a Cisco 4500 or Cisco 7500 router. [CSCdi54277]

• The "BADLINESTATE" message indicates that a frame was received while the router was transmitting. This points to a misconfiguration somewhere in the system because the bisync protocol is supposed to ensure half-duplex operation.

  • If the connecting device is configured FULL-DUPLEX or CONSTANT RTS, configure the interface bsc fdx.

  • The poll-timeout of the connecting HOST might be too short. To recover, issue the shut command on the interface. [CSCdi54541]

• Some NetBIOS applications that require a UI frame in response to Add Name Query cannot connect using a DLSw peer on demand if the NetBIOS circuit is the initial circuit that triggers the peer-on-demand to connect. [CSCdi54796]

• A sniffer trace shows duplicate ring numbers in the RIF when proxy explorers are in use. New SNA sessions fail to connect to the FEP. The workaround is to issue the clear rif command. [CSCdi55032]

• It is not possible to configure more than one DLSw remote peer using direct encapsulation for the same Frame Relay interface. The following error message is produced when the second peer is defined:

%Must remove the remote-peer to change the lf

The workaround is to use TCP encapsulation. [CSCdi55075]

• The dlsw remote-peer frame-relay interface serial command does not work on a point-to-point subinterface. The workaround is to use multipoint and to do LLC mapping. [CSCdi55085]

• A connection to a DLU (DSPU or APPN) across RSRB might fail if the remote SAP address is not enabled at the destination router. The workaround is to enable the remote SAP address. [CSCdi56660]

• DLSw FST encapsulation does not work over WAN, Token Ring, or FDDI interfaces. [CSCdi57207]

• An APPN router might unbind an LU6.2 session after receiving an unsolicited IPM with a nonzero next-window size. [CSCdi57730]

• A FRAS BNN-to-SDLC link does not restart when a Frame Relay interface is power-cycled. After the CSU is powered off, the "fras backup rsrb" kicks to put the SDLLC traffic across the RSRB peers. When the CSU is powered back on and the Frame Relay DLCI comes back up, the FRAS BNN connection to the SDLC nodes does not reactivate, although connections to Token Ring nodes do restart. [CSCdi61156]

• A bus error occurred at PC0x169a46. The stack trace indicates a problem in the LNX process. This problem occurs on X.25. [CSCdi73516]

• When the fast source-route translational bridging feature is configured, packets are corrupted. The workaround is to issue the no source-bridge fastswitch ring-group fastswitch command, which disables the fast source-route translational bridging feature. [CSCdi87612]

• A router configured for DLSw has a buffer leak in the middle and big buffers. Eventually, the router runs out of I/O memory.

The problem is related to the way DLSw backup peers are configured. This problem occurs only if the local router is configured with backup peer commands and the remote router also has a configured peer and is not promiscuous.

The workaround is to remove the DLSw backup peer configuration. [CSCdj21664]

• The backup is not invoked until the interface transitions to the down state. [CSCdj22613]

• When testing FRAS BAN for SDLC attached PU 2.1 and PU 2.0 and using RSRB backup over PSTN, the PUs might fail to connect after the Frame Relay interface is brought back up after a link failure.

The output of the show fras command might show ls-reset backup enabled. To reconnect the PUs, the fras backup rsrb statement must be removed, or the serial interfaces configuration must be deleted and then readded. [CSCdj39306]

• An APPN router might fail the ACT_ROUTE if using parallel transmission groups (TGs). This problem might occur when an APPN router has two parallel links defined with the adjacent node. If the adjacent node activated a link to the network node (NN) requesting a TG number that had previously been used for a different defined link activation, the NN might fail the ACTIVATE_ROUTE. The APPN router sometimes tries to incorrectly activate the route using the other inactive link that has the same TG number. [CSCdj49814]

• Under certain circumstances, APPN might crash with the following stack trace:

> System was restarted by bus error at PC 0x6C75DC[_Mfree(0x6c75b6)+0x26], address 0xFFFFFFF8[_etext(0x73ab50)+0xff8c54a8]
> Image text-base: 0x00012000[__start(0x12000)+0x0], data-base: 0x0073AB50[__etext(0x73ab50)+0x0]
> FP: 0x872C74[_etext(0x73ab50)+0x138124], RA: 0x6588BC[_session_failure_clean_up(0x658502)+0x3ba]
> FP: 0x872EB8[_etext(0x73ab50)+0x138368], RA: 0x65C6E6[_process_cp_status_sig(0x65c2da)+0x40c]
> FP: 0x8730F0[_etext(0x73ab50)+0x1385a0], RA: 0x64D820[_xxxmss00(0x64d64e)+0x1d2]
> FP: 0x873210[_etext(0x73ab50)+0x1386c0], RA: 0xB720C[_process_hari_kari(0xb720c)+0x0]

[CSCdj51051]

• Frames might get corrupted while moving from an Ethernet segment to a FRAS-BAN interface. This is because of a problem in transparent bridging with Frame Relay. This caveat is the same as CSCdj47881. [CSCdj58692]

• When source-route translational bridging is used, LLC sessions initiated from the transparent domain results in the source route's largest frame being incorrectly set to 4472 bytes instead of 1500 bytes. The result is that SNA and NetBIOS sessions might fail if the source-route station sends a frame with a payload that exceeds the maximum allowable size of 1500 bytes for Ethernet media.

The problem typically occurs when NetBIOS is utilized to allow workstations to communicate between Ethernet and Token Ring. It also occurs when SNA is used.

The workaround is to disable fast-switching by using the no source-bridge transparent fastswitch command or configuring the end stations to use frames with a payload of less than or equal to 1500 bytes. [CSCdj62385]

• The APPN router might have an excessive amount of processor memory allocated to APPN after experiencing several spikes in APPN processing. The APPN memory manager should be optimized to release groups of unused pools back to the operating system. [CSCdj62502]

• A Cisco 4500 router running Release 11.2(9.1) might crash when configured for bisync (BSC). [CSCdj65763]

• The router might send a FRMR when the role is primary. The default behavior is changed so that it can only send FRMR as a secondary. If this presents a problem, use the frmr-disable interface configuration option to prevent a FRMR from being sent as a primary or secondary. [CSCdj66967]

• Any DLUR installation with over 800 to 1000 downstream PUs might experience a reload with the following backtrace:

[abort(0x601f2c3c)+0x8]
[crashdump(0x601f0b20)+0x94]
[process_handle_watchdog(0x601c2f08)+0xb4]
[signal_receive(0x601b7d58)+0xa8]
[process_forced_here(0x60169424)+0x68]
[locate_node_index(0x607dbcc0)+0x64]
[etext(0x60849e00)+0xcbee04] [CSCdj67966]

• DSPU over RSRB with FST encapsulation reloads with a bus error similar to the following, when an upstream or downstream connection is initializing:

System was restarted by bus error at PC 0xCC6B8, address 0xFC4AFC82 4000 Software (C4000-JS-M), Version 11.2(10.3), MAINTENANCE INTERIM SOFTWARE Compiled Mon 01-Dec-97 19:45 by ckralik (current version) Image text-base: 0x00012000, data-base: 0x0076AE64

The workaround is to use TCP encapsulation for RSRB or to switch to DLSw. [CSCdj68261]

Interfaces and Bridging

• Running SRB over FDDI on Cisco 4000 series routers might not perform as well as expected. However, this behavior should not seriously impact network functionality. [CSCdi69101]

• On an RSP router, the "%CBUS-3-CTRUCHECK" error message is displayed and the Token Ring interface resets. To correct this problem, upgrade to RSP TRIP Microcode Version 20.1. [CSCdi74639]

• The FDDI interface driver can interact poorly with OSPF during OIR, causing SPF recalculations. This occurs only when OSPF is running on a FDDI interface that is not being inserted or removed. This fix eliminates the spurious indication from the driver that the SPF recalculation needs to take place. [CSCdi81407]

• OIR removal of a FIP from one slot into another will cause the FDDI to permanently remain in DOWN/DOWN. A reload is needed to get it up. OIR removal and putting it back into the same slot works fine. [CSCdi87221]

• A TRIP interface configured for transparent bridging but not configured for source-route bridging might silently drop some incoming frames. Specifically, if the interface receives a frame with a length less than 120 bytes and the RII bit is set (indicating a source-route bridging frame) it might drop the next frame received. This can cause the interface's keepalive processing to fail and can lead to sporadic resets on the interface. [CSCdi88756]

• The error "%CBUS-3-CTRUCHECK: Unit 0, Microcode Check Error" occurs on Token Ring interfaces, causing the interface to reset. [CSCdj08654]

• The POS interface specific configuration commands pos specify-s1s0 and pos specify-c2 do not work correctly. [CSCdj09646]

• Setting encapsulation fddi without bridging enabled on a VIP2/FDDI and FIP in RSP causes the interface to bridge transparently. The encapsulation fddi command should only be used with bridging enabled. As a workaround, use the no bridge-group 1 command to disable bridging. [CSCdj24479]

• The pos specify-s1s0 and pos specify-c2 POS-interface-specific configuration commands do not work correctly. [CSCdj25166]

• When a Token Ring interface is configured with a small MTU size, it could crash when it receives a frame larger than the MTU size. [CSCdj27678]

• The router does not respond to ARPs correctly when bridging IP on a channelized T1 interface. Therefore, Telnets to and from the router will fail. [CSCdj31285]

• Cisco IOS does not correctly return values for Token Ring soft error counters via SNMP. This might cause some SNMP management applications that query the Token Ring MIB to report errors. [CSCdj35713]

• Data corruption has been experienced at high bidirectional traffic rates. Corruption can also occur at high bidirectional traffic rates (when interface is throttling) when issuing the shut command.

Data corruption is possible if you are using Rev2 Mueslix and an release earlier than Release 11.2(9)P. [CSCdj43672]

• TTY lines on access servers might hang when control characters are sent in dumb terminal mode (no PPP or SLIP). A show line shows the TTY line in a ready state, but no response or prompt is seen from the access server when the activation character is sent (default is a return). Doing a clear line # does allow for the line to recover and respond to the activation character. [CSCdj46760]

• A "System restarted by bus error at PC 0x4262AA, address 0xFFFFFFFC" message might be received when the frame-relay payload-compression packet-by-packet command is entered under the subinterface. [CSCdj49344]

• With BVI used to route 802.2, the input queue counters might increment to the limit and then the BVI interface might wedge until the router is reset. One possible workaround is to set the values high enough so the router will stay up until it can be reset. [CSCdj68273]

• When IRB is enabled, the BVI interface might not overwrite the real incoming interface in the ARP response, so an incomplete ARP entry might be installed and "wrong cable" might be listed in the debug arp output. [CSCdj68785]

• The "%LINK-3-TOOBIG: Interface Lex1, Output packet size of= 1520 bytes too big" error might occur on a Cisco 4500 router after upgrading to Cisco IOS Release 11.2(9). [CSCdj69018]

IP Routing Protocols

• A spurious memory access can occur when switching from flow switching to process switching using the no ip route-cache command, and then to back to flow switching using the ip route-cache flow command. [CSCdj08350]

• A routing node is removed from the IP cache Radix tree and then the buffer is freed, but somehow it can still be traversed from the treetop and cause a crash (access after free). [CSCdj17314]

• A crash might occurr because of a memory leak. Output from the show memory command shows "IP Input" and "Pool Manager" holding onto memory. [CSCdj23080]

• Currently, all packets denied by an access list are sent to the process level to generate an ICMP administratively prohibited message. Some of these packets are dropped because Cisco routers limit ICMP generation to two packets per second. This behavior results in excessive CPU load. [CSCdj35407]

• In some instances, a configured BGP router ID is not used after the router reloads. Instead, the router uses the highest IP interface address as its router ID until the clear ip bgp command is executed.

A workaround is to configure a loopback on the interface whose address is greater than any other address on the router. [CSCdj37962]

• If two routing protocols with mutual redistribution cause a routing loop, it is possible that the loop will remain even after updates have been filtered. The problem usually occurs after a clear ip route * command is issued after applying the filters. If the routes are allowed to age out the normal way, the problem does not occur. If OSPF is running, the workaround is to issue the clear ip ospf redistribution command. [CSCdj38397]

• When attempting to set the ipNetToMediaType value with SNMP, the following error is returned and the value is not set:

snmpset: The value given has incorrect type or length. [CSCdj43710]

• In the presence of a large number of subnets, a CPUHOG message similar to the following might be generated:

%SYS-3-CPUHOG: Task ran for 2608 msec (73/65), Process = BGP scanner, PC = 176388

[CSCdj45966]

• Manual summarization with EIGRP does not work correctly. A summary route does not get advertised but one or more of the more specific routes does. [CSCdj46525]

• A router might crash in GRE fast-switching routines without any changes in topology or configuration. [CSCdj50361]

• RIP might cause a "SYS-3-CPUHOG" message. [CSCdj51693]

• Under certain conditions, an LS type 5 is not generated by the ABR in response to a received LS type 7. [CSCdj55301]

• A router might crash when configured with a very large IP accounting threshold. A workaround is to configure a small threshold or to leave it at the default. [CSCdj55512]

• With certain route-map configurations or a soft-reconfiguration, the LOCAL_PREF for a path might be set to zero, resulting in the wrong path being selected. [CSCdj55839]

• Under rare circumstances, a BGP router sends BGP updates with a duplicate community attribute, which triggers the neighbor reset. [CSCdj64103]

• EIGRP topology entries from the redistribution of connected routes where EIGRP is already running natively might not clear when the interface goes down. [CSCdj68388]

• When an interface is configured to send RIP V1 packets while running RIP V2, the router sends out corrupt packets. V2 packets are not affected. There is no known workaround. [CSCdj69026]

ISO CLNS

• If secondary addresses are configured on an unnumbered interface, the interface routes corresponding to these addresses are not advertised in IS-to-IS. A workaround is to number the interface. [CSCdi60673]

• A crash might be caused by an AVL node that is freed but still accessed during tree traversing. This problem is a result of the node being deleted and freed in the middle of tree walk. This is an IS-to-IS(using AVL tree)-specific problem. [CSCdj18685]

• A dynamically discovered CLNS route does not overwrite a static CLNS route pointing to a down interface. As a workaround, remove the static route definition from the configuration and issue the clear clns route command. [CSCdj31228]

LAT

LAT services are not available on the router when IRB is enabled. [CSCdj52841]

LLC Type 2

• A Cisco 4700 router might report intermittent "SYS-2-LINKED" error messages even though there is no memory shortage. [CSCdi52327]

• When running DLSw+ over Ethernet, the router transmits corrupted frames on retransmission. The retransmission occurs on receipt of a REJ frame from the end station or if an acknowledgement of the frame is not received within the LLC2 T1 timeout. [CSCdi52934]

• Timers are not cleaned up properly in LLC2. This might result in crashes when RSRB local acknowledgment is used under a high load. [CSCdj42474]

Miscellaneous

• Netview Service Point acquires but does not free VTY lines. The only way to recover the VTY lines is by using the clear line command. [CSCdi51685]

• A memory leak can occur that is related to the traffic rate and the TCP process. This leak is difficult to reproduce, but can be identified by an input queue wedge on a router configured for RSRB with TCP encapsulation. The output of a show buffer command indicates memory errors. Other symptoms include small buffers being created but not trimmed, and explorers being received with a wrong SNAP type value. [CSCdi54739]

• Packets might become stuck in the input queue of the destination interface if traffic sent over a GRE tunnel is encrypted. The packets become stuck in the input queue when the encrypted session between the peer routers is not established. The not established condition exists when traffic to be encrypted first begins flowing and also when the encrypted session time duration expires. The impact of this caveat can be lessened by configuring the encrypted session timeout to be substantially longer than the 30 minute default with the crypto key-timeout minutes command. [CSCdi90177]

• When a no shut command is issued on the ISDN interface, and logging and logging trap is configured, the router crashes. [CSCdj05365]

• If a CIP TN3270 PU is configured to connect from the host to the CIP via NCP, the link might fail. The workaround is to configure the CIP TN3270 PUs as connecting at the host. [CSCdj07152]

• Configuring both ISL and Multilink Multichassis PPP can cause a memory consistency check failure. The failure might lead to a software forced crash after a few calls have been received. [CSCdj22189]

• HSRP can raise the CPU while the peer HSRP router is reloaded. The problem occurs when there is more than one HSRP group and the two peer routers have many HSRP peers. This caveat addresses HSRP scalability. The workaround is to reduce the HSPP groups, and/or increase the HSRP hello and hold time. Another symptom is that the interface resets go up until HSRP is stabilized. [CSCdj29595]

• An AppleTalk packet traveling through RSM from one VLAN to another receives an improper 802.3 packet length. This affects other network devices that use this field. [CSCdj36862]

• A router running encryption might show "%ALIGN-3-SPURIOUS: Spurious memory access made at 0x60825E" messages. This means that the router had to access from memory twice in order to execute an instruction. It does not affect the connectivity operation of the router. The CPU overhead is minimal. [CSCdj43491]

• BOOTP/DHCP fails when attempted over an encryption session between routers, if the BOOTP/DHCP traffic will be encrypted by matching the access list. This failure also affects any packets that are forwarded by the ip helper address command, such as Windows 95 Netbios over TCP/IP. The workaround is to adjust the access list so that these packets are not encrypted. [CSCdj54355]

• A router might crash after adding a new crypto link. [CSCdj60818]

• RBE from RSP2 to Cisco 4000 over Frame Relay subinterfaces fails; however, other combinations do not fail. [CSCdj65337]

Novell IPX, XNS, and Apollo Domain

• Adding XNS back into a router's configuration after it has been removed might cause a system to restart by bus error. This might only be a one-time event if it occurs at all. [CSCdj16694]

• When using IPX-EIGRP over ISDN with floating static routes, there might be a short delay (about 10 seconds) before the application is able to get through. [CSCdj38031]

• Before a floating static route is installed, a waiting period is observed when the network is down and unreachable. If IPX watchdogs or SPX keepalives arrive during this time, they will be dropped, leading to session timeouts. [CSCdj50629]

• A problem occurs when using a floating static route across an ISDN link and IPX EIGRP is the primary dynamic routing protocol. When the link goes down, the EIGRP route is installed, but after the floating static is configured and the line goes down and then back up, there is no route to that network. The EIGRP route is received but never fully installed because of what seems to be incomplete removal of the floating static route. [CSCdj52947]

TCP/IP Host-Mode Services

Under rare circumstances, a router reload might occur while running TCP to X.25 protocol translation. [CSCdj23230]

Wide-Area Networking

• When a Cisco 4000 with a Basic Rate Interface (BRI) has the isdn tei powerup configuration flag set, the watchdog timeout will crash the router. A workaround is to configure the router with the isdn tei first-call command. [CSCdi45360]

• The AIP cannot be configured to issue idle cells instead of unassigned cells. [CSCdi48069]

• When traffic prioritization is configured on a Frame Relay interface with the command frame-relay priority-dlci-group, the command no fair-queuing should also be configured on the serial interface to achieve effective traffic prioritization. See the associated caveat CSCdi52882. [CSCdi52067]

• When configuring PVCs on the AIP, you might observe a failure to create more PVCs when the number of VCCs configured is well below the maximum allowed. This failure occurs when the number of VPI values used exceeds a limit. The messages that can appear due to this type of failure include the following:

%AIP-3-AIPREJCMD: Interface ATM5/0, AIP driver rejected Setup VC command (error code 0x0008)

%ATM-3-FAILCREATEVC: ATM failed to create VC(VCD=1500, VPI=10, VCI=257) on Interface ATM5/0, (Cause of the failure: Failed to have the driver to accept the VC)

The limit to the number of VPI values used depends on the configuration of the vc-per-vp configuration parameter. When vc-per-vp is 1024 (the default); 33 VPI values can be used. To work around this limitation, implement the atm vc-per-vp command on the particular ATM interface, which lowers the number of VCs per VP. This results in a corresponding increase in the number of VPI values that can be used. [CSCdi67839]

• On a Cisco 4500 or Cisco 4700, a packet might be registered in both the input and output hold queues when going from ATM to other network links. This might affect the values of the input and output queue length fields in the output of the show interface command.

On a Cisco 4500 or Cisco 4700 configured with ATM, another fast network link, and a slow network link, this behavior might have some impact on the overall throughput of the traffic from ATM to another fast network link when the slow link is flooded with too many packets from ATM. However, there are no known environments in which network functionality could be seriously impaired by this. The correct router behavior would be to drop packets over the slow link without affecting the traffic from ATM to another fast link. [CSCdi69441]

• ARP replies are not sent over a PPP multilink interface. As a workaround, you can configure a static ARP on the remote device or disable PPP multilink. [CSCdi88185]

• The transmitter on an ATM interface on a Cisco 4000 series router could hang if PVCs or SVCs are cleared (torn down/ removed using command line interface) when the OUTPUT queue is wedged. [CSCdi90150]

• Configuring STUN peers on a DLSw network causes the DLSw peers to disconnect.The debug on DLSw shows a "DLSw: keepalive failure for peer on interface Serial" message. The STUN process looks like it is intercepting the DLSw keepalives. [CSCdj08875]

• When using DLCI prioritization on a point-to-point Frame Relay subinterface, and one of the DLCIs fails, the subinterface might bounce once or bounce continually during LMI full status reports, depending on whether LMI reports the DLCI as being DELETED or INACTIVE. This behavior is the same for every DLCI defined in the priority-dlci-group.

During normal behavior, the point-to-point subinterface should go down when the primary DLCI fails. If a secondary DLCI fails, the subinterface stays up, but traffic destined for that DLCI only will fail. [CSCdj11056]

• Dynamic DLCI mappings might inadvertently remain mapped after switched virtual circuit teardown, as can be seen using the command show frame-relay map. [CSCdj11851]

• In some circumstances, the system might reload when using the dialer hold queue. As a workaround, configure the no dialer hold-queue command. [CSCdj12397]

• Intermittent ping failure might occur when pinging over a DDR interface using LAPD encapsulation. There is no workaround [CSCdj20072]

• Frame Relay SVC calls might give the following Traceback message:

%SYS-2-LINKED: Bad enqueue of 8F3288 in queue 9570C8
-Process= "LAPF Input", ipl= 6, pid= 36
-Traceback= EBE30 EAA88 4A73B4 4A8E10

[CSCdj29721]

• Back-to-back branch instructions can cause unpredictable results with the MIPS processor. If your processor is found in the no_throttling() function, insert a nop to avoid possible problems. [CSCdj29854]

• In the ISDN Layer2, Layer3, and management entity tasks, memory pointers become invalid. The problem results from a race condition between tasks when memory is freed in one task, and another task attempts to access this now invalid pointer. This scenario has been seen only on ISDN BRI platforms in which a number of the BRI interfaces experience persistent deactivation causing the management entity to be shut down. Add validmem_complete() checks before accessing or freeing pkt, pkg or primitive pointers. [CSCdj40403]

• When ATM traffic-shaping is enabled on an ATM interface along with priority-queueing, priority queuing does not work as desired.

To work around this problem, turn off ATM traffic-shaping over that interface. Another workaround is to use Cisco IOS Release 11.2(2) or earlier, including Release 11.1. [CSCdj45778]

• A problem occurs when memory is low and a show isdn history command is executed. [CSCdj46541]

• When the ip tcp header-compression and ppp multilink commands are configured together on the same interface, the router might crash.

The workaround is to remove the ip tcp header-compression or ppp multilink commands. [CSCdj53093]

• Multilink will only bring one link when used as backup on a DDR interface even though dialer-load threshold is configured. To work around this problem, configure the no ppp multilink command. [CSCdj56109]

• A problem has been identified with traffic shaping on the Cisco 4500 ATM NIMs. [CSCdj56673]

• Under rare conditions, an RSP4 might reload when an FSIP with active HDLC encapsulation interfaces is in use. [CSCdj57591]

• When configuring map-class frame-relay BC committed-burst-size, the system might encounter a CPU exception with reason = EXEC_ADERR(1200) and restart.

There is no workaround, for this intermittent problem. [CSCdj62139]

• When using Frame Relay SVCs, Cisco IOS software appears to not include the magnitude parameters for Be and Bc on the SVC CONNECT message. It only includes them in the SETUP message. The SVC circuits are on S4/0 for both routers. Without the magnitude parameters, the biggest value Bc and Be can be is approximately 130 Kb. There is no known workaround. [CSCdj63173]

• A Frame Relay interface configured for ANSI LMI will acknowledge a Cisco LMI update when the router should ignore it. [CSCdj64207]

• The map-class commands frame-relay bc out and frame-relay be out are accepted by the Enterprise image. These parameters are relevant for SVC setup. However, the traffic shaping code does not use them. As a result, the values appear to be unset. This behavior can be avoided by using the commands frame-relay bc number and frame-relay be number. [CSCdj65624]

• When running LAPB over a DDR interface with dialer hold-queue configured, a traceback error message is generated when dialing out and the call connects. The traceback is not catastrophic but indicates a 20-byte memory leak on every dial attempt. As a workaround, configure the no dialer hold-queue command on the DDR interface. [CSCdj65756]

• The router might reload when booting up an image from a saved X.25 routing configuration. This problem was introduced in Release 11.2(10.1). [CSCdj67115]

• When the system is reducing its rate in response to the receipt of BEcNS, the reduction might not be predictable. Rate adjustments are made once per interval if any number of BECNs are received during that interval. [CSCdj67297]

• Configuring a PVC via the frame-relay interface-dlci command on multipoint subinterfaces causes a system reload if the PVC is previously learned via inverse ARP. [CSCdj67510]

• A BRI interface might lose a TEI after it is reset. The router fails to request a second TEI after the reset. If the BRI is reset a second time, the router regains both of the TEIs. [CSCdj69824]

Caveats for Previous Releases

Possibly unexpected behavior was found in previous releases in the following areas:

• Access Server

• AppleTalk

• Basic System Services

• IBM Connectivity

• Interfaces and Bridging

• IP Routing Protocols

• LAT

• Novell IPX, XNS, and Apollo Domain

• Protocol Translation

• TCP/IP Host-Mode Services

• TN3270

• Wide-Area Networking

A complete list of the caveats, including descriptions and possible workarounds, can be found on CCO or on the Documentation CD-ROM.

On CCO, go to Software and Support and select Documentation. Next, select Documentation, click on Cisco IOS Software Configuration, and then click on Cisco IOS Release 11.2. From the bulleted list, click on Cisco IOS Software Release 11.2 Caveats (All 11.2 Releases).

On the Documentation CD-ROM, go to Cisco Product Documentation, select Cisco IOS Software Configuration, and then select Cisco IOS Release 11.2. From the bulleted list, select Cisco IOS Software Release 11.2 Caveats (All 11.2 Releases).

Cisco Connection Online

Cisco Connection Online (CCO) is Cisco Systems' primary, real-time support channel. Maintenance customers and partners can self-register on CCO to obtain additional information and services.

Available 24 hours a day, 7 days a week, CCO provides a wealth of standard and value-added services to the Cisco customers and business partners. CCO services include product information, product documentation, software updates, release notes, technical tips, the Bug Navigator, configuration notes, brochures, descriptions of service offerings, and download access to public and authorized files.

CCO serves a wide variety of users through two interfaces that are updated and enhanced simultaneously: a character-based version and a multimedia version that resides on the World Wide Web (WWW). The character-based CCO supports Zmodem, Kermit, Xmodem, FTP, and Internet e-mail, and it is excellent for quick access to information over lower bandwidths. The WWW version of CCO provides richly formatted documents with photographs, figures, graphics, and video, as well as hyperlinks to related information.

You can access CCO in the following ways:

• WWW:  http://www.cisco.com

• WWW:  http://www-europe.cisco.com

• WWW:  http://www-china.cisco.com

• Telnet:  cco.cisco.com

• Modem:  From North America, 408 526-8070; from Europe, 33 1 64 46 40 82. Use the following terminal settings: VT100 emulation; databits: 8; parity: none; stop bits: 1; and connection rates up to 28.8 kbps.

For a copy of CCO's Frequently Asked Questions (FAQ), contact cco-help@cisco.com. For additional information, contact cco-team@cisco.com.

Documentation CD-ROM

Cisco documentation and additional literature are available in a CD-ROM, which ships with your product. The Documentation CD-ROM, a member of the Cisco Connection Family, is updated monthly. Therefore, it might be more up to date than printed documentation. To order additional copies of the Documentation CD-ROM, contact your local sales representative or call customer service. The CD-ROM is available as a single unit or as an annual subscription. You can also access Cisco documentation on the World Wide Web at http://www.cisco.com, http://www-china.cisco.com, or http://www-europe.cisco.com.