Table of Contents

Contents
Introduction

Cisco 2600 Series Routers
Early Deployment Releases

System Requirements

Memory Requirements
Hardware Supported
Determining Your Software Release
Upgrading to a New Release
Feature Set Tables

New and Changed Information
Important Notes

Deprecated MIBs

Caveats

Open Caveats - Release 12.0(2)XC

Basic System Services
IP Routing Protocols
Miscellaneous
Novell IPX, XNS, and Apollo Domain
Wide-Area Networking

Resolved Caveats - Release 12.0 T

Security Problem
IP Routing Protocols
Miscellaneous
Novell IPX, XNS, and Apollo Domain

Related Documentation

Release-Specific Documents
Platform-Specific Documents
Feature Modules
Cisco IOS Software Document Set

Documentation Modules
Release 12.0 Documentation Set

Service and Support

Software Configuration Tips on the Cisco TAC Home Page

Cisco Connection Online
Documentation CD-ROM

Release Notes for Cisco  2600 Series for Cisco  IOS Release  12.0(2)XC

January 7, 1999

These release notes describe new features for the Cisco  2600 series routers that support Cisco  IOS Release  12.0(2)XC. Cisco  IOS Release  12.0(2)XC is based on Cisco  IOS Release  12.0(2)T.

Use these release notes in conjunction with the cross-platform Release Notes for Cisco IOS Release  12.0 T  located on Cisco  Connection Online (CCO)  and the Documentation CD-ROM.

For a list of software caveats that apply to Release 12.0(2)XC, refer to the "Caveats" section.

Contents

These release notes discuss the following topics:

• Introduction

• System Requirements

• New and Changed Information

• Important Notes

• Caveats

• Related Documentation

• Service and Support

• Cisco Connection Online

• Documentation CD-ROM

Introduction

This section provides information about the Cisco 2600 series routers and Early Deployment Releases (ED) for the Cisco 2600 series routers.

Cisco 2600 Series Routers

Cisco Systems extends enterprise-class versatility, integration, and power to branch offices with the Cisco 2600 series modular access router family. The Cisco 2600 series routers are cost-effective, modular access routers designed to enable customers to easily adopt future technologies and scale to accommodate network expansion, thereby protecting the customer's investment. The Cisco 2600 series shares modular interfaces with the Cisco 1600, Cisco 1700, and Cisco 3600 series, providing a cost-effective solution to meet today's branch office needs for applications such as:

• Secure Internet/intranet access

• Multiservice voice/data integration

• Analog and digital dial access services

• Virtual Private Network (VPN) access

• Inter-VLAN routing

The Cisco 2600 series modular architecture provides the versatility needed to adapt to changes in network technology as new services and applications become available. Driven by a powerful reduced instruction set computer (RISC) processor, the Cisco 2600 series supports the advanced Quality of Service (QoS), security, and network integration features required in today's evolving enterprise networks.

Early Deployment Releases

This release note document is based on Cisco IOS Release 12.0(2)T. Release 12.0 T is an Early Deployment (ED) release, delivering fixes to software caveats and support for new Cisco hardware. Use the information in this section to determine which early deployment release you require.

• Release 12.0(2)T is an ED release with no addtional software or hardware features from the previous release.

  • ISDN basic rate interface (BRI) Voice over IP (VoIP) is not supported in Release 12.0(2)T.

  • Cisco 2620 and Cisco 2621 routers with 10/100 Ethernet interfaces are not supported in Release 12.0(2)T.

  • Cisco IOS firewall images are supported in Release 12.0(2)T.

• Release 12.0(2)XD is an ED release with the additional functionality of the ISDN BRI VoIP voice interface card, which provides narrowband digital voice connectivity in Cisco VoIP.

  • ISDN BRI VoIP is supported in Release 12.0(2)XD.

  • Cisco 2620 and Cisco 2621 routers with 10/100 Ethernet interfaces are not supported in Release 12.0(2)XD.

  • Cisco IOS firewall images are supported in Release 12.0(2)XD

• Release 12.0(2)XC is an ED release with two additional platforms---the Cisco 2620 and the Cisco 2621.The Cisco 2620 router supports the 1-port 10/100 Ethernet interface, and the Cisco 2621 router supports the 2-port 10/100 Ethernet interface.

  • ISDN BRI VoIP is not supported in Release 12.0(2)XC.

  • Cisco 2620 and Cisco 2621 routers with 10/100 Ethernet interfaces are supported in Release 12.0(2)XC.

  • Cisco IOS firewall images are supported in Release 12.0(2)XC.

• Release 11.3(7)T is an ED release with no additional software or hardware features from the previous release.

  • ISDN BRI VoIP is not supported in Release 11.3(7)T.

  • Cisco 2620 and Cisco 2621 routers with 10/100 Ethernet interfaces are not supported in Release 11.3(7)T.

  • Cisco Firewall images are not supported in Release 11.3(7)T.

The following table briefly describes some of the ED releases available now and soon to be available for the Cisco 2600 series.

Table 1: Early Deployment Releases for the Cisco 2600 Series

ED Release	Maintenance Release	Additional Software Features	Additional Hardware Features	Additional Feature Sets	Availability
Release 12.0 T	2	---	---	IP/FW IP/FW Plus IPSec 56 IP/IPX/AT/DEC/FW Plus Enterprise F/W IPSec 56	Now
Release 12.0 XC	2	---	Cisco 2620 and Cisco  2621 with Fast Ethernet 1- or 2-port 10/100 Ethernet for the Cisco  2620 and Cisco  2621	IP/FW IP/FW Plus IPSec 56 IP/IPX/AT/DEC/FW Plus Enterprise F/W IPSec 56	Now
Release 12.0 XD	2	---	ISDN BRI VoIP Voice Interface Card	IP/FW Plus IPSec 56 IP/IPX/AT/DEC/FW Plus Enterprise F/W IPSec 56	Now
Release 11.3 T	7	---	---	---	Now

System Requirements

This section describes the system requirements for Release 12.0(2)XC and includes the following subsections:

• Memory Requirements

• Hardware Supported

• Determining Your Software Release

• Upgrading to a New Release

• Feature Set Tables

Memory Requirements

Table 2 describes the memory requirements of the Cisco  IOS feature sets for the Cisco  2600 series for Release  12.0(2)XC. All "Plus" feature sets include voice network support.

Table 2: Memory Requirements for the Cisco  2600 Series

Feature Set by Platform	Image Name	Required Flash Memory	Required DRAM Memory	Runs From
IP	c2600-i-mz	4 MB	20 MB	RAM
IP Plus	c2600-is-mz	8 MB	24 MB	RAM
IP Plus 40	c2600-is40-mz	8 MB	24 MB	RAM
IP Plus 56	c2600-is56-mz	8 MB	24 MB	RAM
IP Plus IPsec 56	c2600-is56i-mz	8 MB	24 MB	RAM
IP/FW	c2600-io-mz	4 MB	20 MB	RAM
IP/IPX/AT/DEC	c2600-d-mz	8 MB	20 MB	RAM
IP/IPX/AT/DEC Plus	c2600-ds-mz	8 MB	24 MB	RAM
IP/IPX/AT/DEC/FW Plus	c2600-dos-mz	8 MB	24 MB	RAM
IP IPsec 3DES	c2600-ik2s-mz	8 M	24 MB	RAM
IP/FW IPsec 3DES	c2600-ik2os-mz	8 MB	24 MB	RAM
IP/FW Plus IPsec 56	c2600-ios56i-mz	8 MB	24 MB	RAM
Enterprise Plus	c2600-js-mz	8 MB	32 MB	RAM
Enterprise Plus 40	c2600-js40-mz	8 MB	32 MB	RAM
Enterprise Plus 56	c2600-js56-mz	8 MB	32 MB	RAM
Enterprise Plus IPsec 56	c2600-js56i-mz	8 MB	32 MB	RAM
Enterprise/APPN Plus	c2600-ajs-mz	8 MB	32 MB	RAM
Enterprise/APPN Plus 40	c2600-ajs40-mz	8 MB	32 MB	RAM
Enterprise/APPN Plus 56	c2600-ajs56-mz	8 MB	32 MB	RAM
Enterprise/APPN IPsec 3DES	c2600-ajk2s-mz	8 MB	32 MB	RAM
Enterprise/APPN Plus IPsec 56	c2600-ajs56i-mz	8 MB	32 MB	RAM
Remote Access Server	c2600-c-mz	4 MB	20 MB	RAM

Hardware Supported

Cisco IOS Release 12.0 supports the following Cisco  2600 series routers:

• Cisco  2610

• Cisco  2611

• Cisco  2612

• Cisco  2613

• Cisco 2620 (requires Cisco IOS Release 12.0(2)XC)

• Cisco 2621 (requires Cisco IOS Release 12.0(2)XC)

For detailed descriptions of the new hardware features for Release 12.0, refer to the cross-platform Release Notes for Cisco IOS Release 12.0  T.   Table 3 lists the interfaces supported by the Cisco 2600 series.

Table 3: Supported Interfaces on the Cisco  2600 Series

Interface, Network Module, or Data Rate1		Platforms Supported
LAN Interfaces	Ethernet (10BaseT), 1- or 2-port	Cisco  2610, Cisco  2611, Cisco  2612
	Token Ring (RJ-45), 1-port	Cisco  2612, Cisco  2613
	10/100 Ethernet, 1-or 2-port	Cisco 2620 and Cisco 2621
LAN Network Modules	Ethernet, 4-port	All Cisco  2600 series platforms
	Ethernet, 1-port	All Cisco  2600 series platforms
	ATM-25 RJ-45 interface, 1-port	All Cisco  2600 series platforms
Serial Network Modules	Asynchronous, 16- or 32-port	All Cisco  2600 series platforms
	Asynchronous/Synchronous Serial low speed (128 kbps max), 4- or 8-port	All Cisco  2600 series platforms
Dial, ISDN and Channelized Serial Network Modules	Channelized T1/ISDN PRI, 1- or 2-port	All Cisco  2600 series platforms
	Channelized T1/ISDN PRI with CSU, 1- or 2-port	All Cisco  2600 series platforms
	Channelized E1/ISDN PRI balanced, 1- or 2-port	All Cisco  2600 series platforms
	Channelized E1/ISDN PRI unbalanced, 1- or 2-port	All Cisco  2600 series platforms
	ISDN BRI S/T interface, 4-or 8-port	All Cisco  2600 series platforms
	ISDN BRI U (NT1) interface, 4- or 8-port	All Cisco  2600 series platforms
	Analog Modems, 8 or 16	All Cisco  2600 series platforms
Voice/Fax Network Module	Voice /Fax, 1 or 2 Voice Interface Card Slots	All Cisco  2600 series platforms
WAN Interface Cards and Voice Interface Cards	ISDN BRI S/T interface (requires external NT1), 1-port	All Cisco  2600 series platforms
	ISDN BRI (NT1) U, 1-port	All Cisco  2600 series platforms
	56/64-kbps DSU/CSU, 1-port	All Cisco  2600 series platforms
	T1/Fractional T1 with DSU/CSU, 1-port	All Cisco  2600 series platforms
	High-Speed Serial (up to 2.048 Mbps), 1-port	All Cisco  2600 series platforms
	Dual High-speed Serial (up to 2.048 Mbps; asynchronous/synchronous support), 2-port	All Cisco  2600 series platforms
	Asynchronous/Synchronous (up to 128 kbps), 2-port	All Cisco  2600 series platforms
	FXS Voice/Fax interface card for Voice/Fax network module, 2-port2	All Cisco  2600 series platforms with Voice/Fax network module
	FXO Voice/Fax interface card for Voice/Fax network module, 2-port2	All Cisco  2600 series platforms with Voice/Fax network module
	E&M Voice/Fax interface card for Voice/Fax network module, 2-port2	All Cisco  2600 series platforms with Voice/Fax network module
Advanced Integration Modules	Data Compression AIM (up to 8.192Mbps)	All Cisco  2600 series platforms

1The Voice/Fax and ATM-25 network modules require Cisco IOS Plus feature sets. 2This interface card requires the NM-1V or NM-2V network module.

Determining Your Software Release

To determine the version of Cisco IOS software currently running on a Cisco  2600 router, log into the router and use the show version EXEC command. The following is sample output from the show version command. The version number is indicated on the second line as shown below:

Cisco Internetwork Operating System Software 
IOS (tm) 2600 Software (c2600-i-mz), Version 12.0(2)XC, RELEASE SOFTWARE
 

Additional command output lines include more information, such as processor revision numbers, memory amounts, hardware IDs, and partition information.

Upgrading to a New Release

For information on updating to a new software release, refer to the Cisco IOS Software Release Upgrade Paths and Packaging Simplification product bulletin located on CCO. On CCO, follow this path: Products & Ordering: More Information: Product Bulletins. Scroll to Software. Under Cisco IOS 12.0, click the Upgrade Paths bulletin.

Feature Set Tables

Cisco IOS software is packaged in feature sets (also called software images) depending on the platform. Each feature set contains a specific set of Cisco IOS features. The following section lists the feature set matrix and the features supported by each feature set.

The feature set matrix (Table 4) shows the feature set organization and lists which feature sets are available on the Cisco 2600 series for Release  12.0(2)XC. Table 4 lists the feature set name, the feature set matrix term, the software image name, and the supported platforms.

Table 4: Feature Sets Supported by the Cisco  2600 Series

Feature Sets		Feature Set Matrix Term	Software Image	Platforms
IP Standard Feature Sets	IP	Basic1	c2600-i-mz	All Cisco  2600 series platforms
	IP Plus	Basic, Plus2	c2600-is-mz	All Cisco  2600 series platforms
	IP Plus 40	Plus, Plus  403	c2600-is40-mz	All Cisco  2600 series platforms
	IP Plus 56	Plus, Plus  564	c2600-is56-mz	All Cisco  2600 series platforms
	IP Plus IPsec 56	Plus, Plus  IPsec  565	c2600-is56i-mz	All Cisco  2600 series platforms
IP/IPX/AppleTalk/ DEC Standard Feature Sets	IP/IPX/AppleTalk/ DEC	Basic	c2600-d-mz	All Cisco  2600 series platforms
	IP/IPX/AppleTalk/ DEC Plus	Basic, Plus	c2600-ds-mz	All Cisco  2600 series platforms
Enterprise Standard Feature Sets	Enterprise Plus	Plus	c2600-js-mz	All Cisco  2600 series platforms
	Enterprise Plus 40	Plus, Plus  40	c2600-js40-mz	All Cisco  2600 series platforms
	Enterprise Plus 56	Plus, Plus  56	c2600-js56-mz	All Cisco  2600 series platforms
	Enterprise Plus IPsec 56	Plus, Plus  IPsec  56	c2600-j56i-mz	All Cisco  2600 series platforms
Enterprise/APPN Standard Feature Sets	Enterprise/APPN Plus	Plus	c2600-ajs-mz	All Cisco  2600 series platforms
	Enterprise/APPN Plus 40	Plus, Plus  40	c2600-ajs40-mz	All Cisco  2600 series platforms
	Enterprise/APPN Plus 56	Plus, Plus  56	c2600-ajs56-mz	All Cisco  2600 series platforms
	Enterprise/APPN Plus IPsec 56	Plus, Plus IPSec 56	c2600-ajs56i-mz	All Cisco  2600 series platforms
Remote Access Server Feature Set	Remote Access Server	Basic	c2600-c-mz	All Cisco  2600 series platforms

1This feature is offered in the Basic feature set. 2This feature is offered in the Plus feature set. 3This feature is offered in the encryption feature sets which consist of 40-bit (Plus 40) data encryption feature sets. 4This feature is offered in the encryption feature sets which consist of 56-bit (Plus 56) data encryption feature sets. 5This feature is offered in the encryption feature sets which consist of IPsec 56-bit (Plus IPsec 56) data encryption feature sets.

Caution Cisco IOS images with strong encryption (including, but not limited to, 56-bit data encryption feature sets) 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.

Table 5 and Table 6 list the features and feature sets supported by the Cisco 2600 series in Cisco IOS Release 12.0(2)XC. Both tables use the following conventions to identify features:

• Yes---The feature is supported in the feature set.

• No---The feature is not supported in the feature set.

Table 5: Feature List by Feature Set for the Cisco 2600 Series --- Part 1 of 2

	Feature Sets
Features	IP	IP PLUS	IP PLUS 40	IP PLUS 56	IP PLUS IPSEC 56	IP/IPX/AT/DEC	IP/IPX/AT/DEC PLUS
IBM Support
Bridging Code Rework	Yes	Yes	Yes	Yes	Yes	Yes	Yes
RIF Passthru in DLSw+	No	Yes	Yes	Yes	Yes	No	Yes
IP Routing
IP Precedence for GRE Tunnels (GRE VPN)	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Protocol- Independent Multicast (PIM) Version 2	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Management
SNMP Inform Request	No	No	No	No	No	No	No
VPDN MIB and Syslog Facility	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Scalability
Airline Product Set (ALPS)	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Cisco IOS File System	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Entity MIB	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Expression MIB	Yes	Yes	Yes	Yes	Yes	Yes	Yes
OSPF Point to Multipoint	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Per Port Debugging (Conditionally Triggered Debugging)	Yes	Yes	Yes	Yes	Yes	Yes	Yes
SNMP Manager	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Security
Additional Vendor- Proprietary RADIUS Attributes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Authenticating ACLs	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Automated Double Authentication	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Certificate Authority Interoperability	No	No	No	No	Yes	No	No
Internet Key Exchange Security Protocol	Yes	Yes	No	No	No	No	No
IPSec Network Security	No	No	No	No	Yes	No	No
MS-CHAP Support	No	No	No	No	No	No	No
Security (continued)
Named Method Lists for AAA Authentication & Accounting	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Subblock Phase 1	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Switching
Enhanced ATM VC Configuration and Management	Yes	No	No	No	No	Yes	Yes
Multiple ISDN Switch Types	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Voice/Multimedia
VoIP/Symphony	No	No	No	No	No	No	Yes
WAN Optimization
ATM PVC Management	Yes	Yes	Yes	Yes	Yes	No	Yes
DRP Server Agent	Yes	Yes	Yes	Yes	Yes	Yes	Yes
WAN Services
Always On/Dynamic ISDN (AO/DI)	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Dialer Watch	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Interface Name Modularity	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Microsoft Point-to-Point Compression (MPPC)	Yes	Yes	Yes	Yes	Yes	Yes	Yes
MS Callback	Yes	Yes	Yes	Yes	Yes	Yes	Yes
National ISDN Switch Types	Yes	Yes	Yes	Yes	Yes	Yes	Yes
New and Changed Show Commands for the Cisco 2600 Series Routers	Yes	Yes	No	No	No	Yes	Yes
Stackable Home Gateway	No	Yes	Yes	Yes	Yes	No	Yes

New and Changed Information

This section lists some of the features available for the Cisco 2600 series in Cisco IOS Release 12.0(2)XC software. For more information about these features, refer to the cross-platform Release Notes for Cisco IOS Release 12.0  T  located on Cisco Connection Online (CCO), the Documentation CD-ROM.

• Additional Vendor-Proprietary RADIUS Attributes

• Always On/Dynamic ISDN (AO/DI)

• ATM PVC Management

• Automated Double Authentication

• Certificate Authority Interoperability

• Dialer Watch

• DRP Server Agent Enhancements

• Fast Ethernet

• Internet Key Exchange Security Protocol

• Microsoft Challenge Handshake Authentication Protocol Support (MS-CHAP)

• Microsoft Point-to-Point Compression (MPPC)

• MS Callback

• Multiple ISDN Switch Types

• Named Method Lists for AAA Authorization and Accounting

• National ISDN Switch Types

• Protocol-Independent Multicast (PIM) Version 2

• RIF Passthru in DLSw+

• SNMP Inform Requests

• Voice over IP

• VPDN MIB and Syslog Facility

Important Notes

This section contains important information about use of your Cisco IOS Release 12.0(2)XC software.

Deprecated MIBs

Older Cisco Management Information Bases (MIBs) will be replaced in a future release. OLD-CISCO-* MIBS are currently being migrated into more scalable MIBs, without affecting existing Cisco IOS products or NMS applications. Application developers should update from deprecated MIBs to the replacement MIBs as shown in the table below.

Deprecated MIB	Replacement
OLD-CISCO-APPLETALK-MIB	RFC1243-MIB
OLD-CISCO-CHASSIS-MIB	ENTITY-MIB
OLD-CISCO-CPUK-MIB	In Development
OLD-CISCO-DECNET-MIB
OLD-CISCO-ENV-MIB	CISCO-ENVMON-MIB
OLD-CISCO-FLASH-MIB	CISCO-FLASH-MIB
OLD-CISCO-INTERFACES-MIB	IF-MIB CISCO-QUEUE-MIB
OLD-CISCO-IP-MIB
OLD-CISCO-MEMORY-MIB	CISCO-MEMORY-POOL-MIB
OLD-CISCO-NOVELL-MIB	NOVELL-IPX-MIB
OLD-CISCO-SYS-MIB	(Compilation of other OLD* MIBS)
OLD-CISCO-SYSTEM-MIB	CISCO-CONFIG-COPY-MIB
OLD-CISCO-TCP-MIB	CISCO-TCP-MIB
OLD-CISCO-TS-MIB
OLD-CISCO-VINES-MIB	CISCO-VINES-MIB
OLD-CISCO-XNS-MIB

Caveats

This section contains open and resolved caveats for the current Cisco IOS maintenance release only. For information on caveats in the Cisco IOS Release 12.0  T, refer to the "Caveats" section in the cross-platform Release Notes for Cisco IOS Release 12.0  T  document located on CCO and the Documentation CD-ROM. This section contains caveats affecting all maintenance releases.

Open Caveats - Release 12.0(2)XC

This section describes possibly unexpected behavior by Release 12.0(2)XC. Unless otherwise noted, these caveats apply to all 12.0 releases up to and including 12.0(2)XC.

Basic System Services

• CSCdk57339

The [no] atm rmon collect group-num does not properly take effect when invoked. The ATM-RMON feature (available only on the LS-1010 platform) is fully functional, except the assignment of ATM interfaces to ATM-RMON collection groups must be done by setting the associated MIB objects with SNMP. See the portSelTable definitions in the ATM-RMON-MIB.my MIB document for more information.

• CSCdk23300

There might be an issue with a second call being placed to a station that is currently in call_setup or connected. This only appears where the call is being forwarded via an intermediate router.

IP Routing Protocols

• CSCdk52224

When using sparse-mode PIM multicast, it might take up to five minutes from boot up of the routers until the multicast tree stabilizes. During this period, PATH messages sent to multicast addresses will not be delivered, and hence RSVP path and reservation sessions will not be established. This is a transient phenomenon which occurs only when the routers are being booted. Once the multicast tree stabilizes, paths/reservations are established quickly.

This problem does not occur in unicast or dense-mode multicast networks.

Miscellaneous

• CSCdk45102

The Token-Ring Inter-Switch Link (TR-ISL) feature is currently not supported on either the Cisco 3620 or Cisco 3640. There is no workaround.

• CSCdk51439

If flow-acceleration is enabled and subsequently disabled and if encryption is also subsequently enabled, the router might unexpectedly reload.

• CSCdk56804

Under rare circumstances, if an incoming call is terminated by the caller, the IP portion of the call might not be terminated correctly. This only occurs under very specific timing conditions.

• CSCdk67063

ALPS UTS serial encapsulation could not be configured.

• CSCdk67834

Cisco 800 routers can experience a page leak after prolonged usage. This condition is rare (roughly 1 in 50 units experience it) and might take several days to manifest, depending on the number of calls.

When this problem occurs, performance degrades until the unit thrashes (for example, runs so slow that no useful work is accomplished). This is accompanied by continuous and heavy blinking of the OK LED.

Disabling multilink and STAC compression might reduce or eliminate the leak. A soft or hard reset (for example, using the reload or power-cycle command) is the only way to clear the problem when it occurs.

To cause a leak, the router must allocate a large block of memory, read from that memory, deallocate the block, allocate another large block, and write to it without reading from it. The alloc/read/free case (without any intervening writes) is very rare and typically only occurs during call setup failure with multilink (MLPPP) and/or compression configured.

Novell IPX, XNS, and Apollo Domain

• CSCdk67783

IPX allows the primary interface and multiple ISL subinterfaces to have the same IPX network number and encapsulation.

Workaround: Don't configure interfaces with the same IPX network number.

Wide-Area Networking

• CSCdk41155

ARP replies out a bridged PPP over ATM with IRB interface will fail to be sent. To intall the ARP entries, initiate traffic from the router and force an incoming ARP reply.

• CSCdk68516

Removing a dialer interface while a call is up can result in the loss of use of one B channel. A reload of the router will bring it back.

Resolved Caveats - Release 12.0 T

All the caveats listed in this section are resolved in release 12.0(2)T.

Security Problem

• CSCdk77426

If a User Datagram Protocol (UDP) packet with an invalid length is sent to port 514 (the "syslog" port) on an IOS device, the device is likely to reload. In this situation, a stack trace might not be saved. Such packets are sent by the popular nmap port scanning program.

Workaround:

You can work around this vulnerability by preventing any affected Cisco IOS device from receiving or processing UDP datagrams addressed to its port 514. This can be done either using packet filtering on surrounding devices, or by using input access list filtering on the affected IOS device itself.

If you use an input access list, that list should be applied to all interfaces to which attackers may be able to send datagrams. This includes not only physical LAN and WAN interfaces, but virtual subinterfaces of those physical interfaces, as well as virtual interfaces and/or interface templates corresponding to GRE, L2TP, L2F, and other tunnelling protocols.

The input access list must block traffic destined for any of the Cisco IOS device's own IP addresses, as well as for any broadcast or multicast addresses on which the Cisco IOS device may be listening. It's important to remember to block old-style "all-zeroes" broadcasts as well as new-style "all-ones" broadcasts.

There is no single input access list that will work in all configurations. It is very important that you understand the effect of your access list in your specific configuration before you activate the list.

The following example shows a possible access list for a three-interface router, along with the configuration commands needed to apply that access list. The example assumes no need for input filtering other than as a workaround for this vulnerability.

! Deny all multicasts, and all unspecified-net broadcasts, to port 514 
      access-list 101 deny udp any 224.0.0.0 31.255.255.255 eq 514 
      ! Deny old-style unspecified-net broadcasts 
      access-list 101 deny udp any host 0.0.0.0 eq 514 
      ! Deny network-specific broadcasts. This example assumes that all of 
      ! the local interfaces are on the class B network 172.16.0.0, subnetted 
      ! everywhere with mask 255.255.255.0. This will differ from network 
      ! to network. Note that we block both new-style and old-style broadcasts. 
      access-list 101 deny udp any 172.16.0.255 0.0.255.0 eq 514 
      access-list 101 deny udp any 172.16.0.0   0.0.255.0 eq 514 
      ! Deny packets sent to the addresses of our own network interfaces. 
      access-list 101 deny udp any host 172.16.1.1 eq 514 
      access-list 101 deny udp any host 172.16.2.1 eq 514 
      access-list 101 deny udp any host 172.16.3.3 eq 514 
      ! Permit all other traffic (default would be to deny) 
      access-list 101 permit ip any any 
 
      ! Apply the access list to the input side of each interface 
      interface ethernet 0 
      ip address 172.16.1.1 255.255.255.0 
      ip access-group 101 in 
 
      interface ethernet 2 
      ip address 172.16.2.1 255.255.255.0 
      ip access-group 101 in 
 
      interface ethernet 3 
      ip address 172.16.3.3 255.255.255.0 
      ip access-group 101 in 

It can be complicated to list all possible addresses, and especially all possible broadcast addresses, to which attack packets might be sent. If you do not expect to receive any legitimate syslog traffic on an interface, you may wish to simply block all syslog traffic arriving on that interface. Remember that this will affect traffic routed through the Cisco IOS device as well as traffic destined to the device.

Input access lists have an impact on system performance, and should be installed with a degree of caution, especially on systems that are running very near their capacity limits.

IP Routing Protocols

• CSCdk37843

Workaround:

The workaround is to configure "router rip" on the router first, before configuring the address on the interface.

Miscellaneous

• CSCdk38476

RADIUS accounting does not work if you have separate authentication and accounting servers.

• CSCdk41902

An IP client might not be able to ping the Route Switch Module (RSM). This situation might occur during Token-Ring Virtual LAN (TR VLAN) configuration on the RSM. It is most common when the IP client sends an address resolution protocol (ARP) without a routing information field (RIF), then sends an ARP with a RIF. The situation might also occur if the concentrator relay function (CRF), to which the client is connected, is configured for source-route bridging (SRB). Workaround: Change the CRF mode from SRB to source-route transparent (SRT) bridging.

Novell IPX, XNS, and Apollo Domain

• CSCdk52372

The Internetwork Packet Exchange (IPX) input process might run out of stack, causing a system reload or reduced performance. There is no workaround.

Related Documentation

The following sections describe the documentation available for the Cisco  2600 series routers. Typically, these documents consist of hardware installation guides, software installation guides, Cisco IOS configuration and command references, system error messages, and feature modules, which are updates to the Cisco IOS documentation. Documentation is available as printed manuals or electronic documents, except for feature modules, which are available online only.

The most up-to-date documentation can be found on the Web via Cisco  Connection Online (CCO)  and the Documentation CD-ROM.  These electronic documents might contain updates and modifications made after the hard copy documents were printed.

These release notes should be used in conjunction with the documents listed in these sections:

• Release-Specific Documents

• Platform-Specific Documents

• Feature Modules

• Cisco IOS Software Document Set

Release-Specific Documents

The following documents are specific to Release  12.0. They are located on CCO and the Documentation CD-ROM:

• Release Notes for Cisco IOS Release 12.0  

To navigate to Release Notes for Cisco IOS Release 12.0, follow this path on CCO  or the Documentation CD-ROM:  

Products & Ordering: Cisco Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Release Notes

• For more information including product bulletins, field notices, and other information relating to a specific software release, refer to the Software Center  located on CCO.

To navigate to the Software Center, follow this path on CCO:

Software & Support: Software Center

Platform-Specific Documents

The following documents are specific to the Cisco 2600 series and are available online at Cisco  Connection Online (CCO)  and on the Documentation CD-ROM:

• Cisco 2600 Series Cabling and Setup Quick Start Guide

• Cisco 2600 Series Hardware Installation Guide

• Network Module Hardware Installation Guide

• Update to Network Modules Hardware Installation Guide

• WAN Interface Cards Hardware Installation Guide

• Update to WAN Interface Cards Hardware Installation Guide

• Cisco 2600 Series Configuration Notes

• Cisco 2600 Series Cable Specifications

To access platform documents on CCO, follow this path:

Products & Ordering: Cisco Documentation: Access Servers and Access Routers: Modular Access Routers: Cisco 2600 Series Routers

To access platform documents on the Documentation CD-ROM, follow this path:

Cisco Product Documentation: Access Servers & Access Routers: Modular Access Routers: Cisco 2600 Series Routers

Feature Modules

Feature modules describe new features supported by Release 12.0(2)XC and 12.0(2)T, and are an update to the Cisco  IOS documentation set. They consist of a brief overview of the feature, benefits, configuration tasks, and a command reference. As updates, the features modules are available online only. The feature module information is included in the next printing of the Cisco IOS documentation set.

To access the feature modules on CCO, follow this path:

Products & Ordering: Cisco Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: New Feature Documentation: New Features in Release 12.0 T

To access the feature modules on the Documentation CD-ROM, follow this path:

Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: New Feature Documentation: New Features in Release 12.0 T

Cisco IOS Software Document Set

The Cisco IOS software documentation set consists of the Cisco IOS configuration guides, Cisco  IOS command references, and several other supporting documents. These documents are shipped with your order in electronic form on the Documentation CD-ROM, unless you specifically ordered the printed versions.

Documentation Modules

Each module in the Cisco IOS documentation set 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.

To access these documents on CCO, follow this path:

Products & Ordering: Cisco Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Configuration Guides & Command References: Cisco IOS Interface Configuration Guide or Cisco IOS Interface Command Reference

To access these documents on the Documentation CD-ROM, follow this path:

Cisco IOS Software Configuration: Cisco IOS Release 12.0: Configuration Guides & Command References: Cisco IOS Interface Configuration Guide or Cisco IOS Interface Command Reference

Release 12.0 Documentation Set

Table 7 details the contents of the Cisco IOS Release 12.0 software documentation set. The document set is available in electronic form, and also in printed form upon request.

To access the Cisco IOS documentation set on CCO, follow this path:

Products & Ordering: Cisco Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0

To access the Cisco IOS documentation set on the Documentation CD-ROM, follow this path:

Cisco IOS Software Configuration: Cisco IOS Release 12.0

Table 7: Cisco IOS Software Documentation Set for Release 12.0

Books	Chapter Topics
Configuration Fundamentals Configuration Guide Configuration Fundamentals Command Reference	Configuration Fundamentals Overview Cisco IOS User Interfaces File Management System Management
Bridging and IBM Networking Configuration Guide Bridging and IBM Networking Command Reference	Transparent Bridging Source-Route Bridging Token Ring Inter-Switch Link Remote Source-Route Bridging DLSw+ STUN and BSTUN LLC2 and SDLC IBM Network Media Translation DSPU and SNA Service Point SNA Frame Relay Access Support APPN Cisco Database Connection NCIA Client/Server Topologies Cisco Mainframe Channel Connection Airline Product Set
Dial Solutions Configuration Guide Dial Solutions Command Reference	Dial-In Port Setup Dial-In Terminal Services Dial-on-Demand Routing (DDR) Dial Backup Dial-Out Modem Pooling Large-Scale Dial Solutions Cost-Control Solutions ISDN X.25 over ISDN VPDN Dial Business Solutions and Examples
Cisco IOS Interface Configuration Guide Cisco IOS Interface Command Reference	Interface Configuration Overview
Network Protocols Configuration Guide, Part 1 Network Protocols Command Reference, Part 1	IP Addressing IP Services IP Routing Protocols
Network Protocols Configuration Guide, Part 2 Network Protocols Command Reference, Part 2	AppleTalk Novell IPX
Network Protocols Configuration Guide, Part 3 Network Protocols Command Reference, Part 3	Apollo Domain Banyan VINES DECnet ISO CLNS XNS
Security Configuration Guide Security Command Reference	AAA Security Services Security Server Protocols Traffic Filtering and Firewalls IP Security and Encryption Passwords and Privileges Neighbor Router Authentication IP Security Options
Cisco IOS Switching Services Configuration Guide Cisco IOS Switching Services Command Reference	Switching Paths for IP Networks Virtual LAN (VLAN) Switching and Routing
Wide-Area Networking Configuration Guide Wide-Area Networking Command Reference	ATM Frame Relay SMDS X.25 and LAPB
Voice, Video, and Home Applications Configuration Guide Voice, Video, and Home Applications Command Reference	Voice over IP Voice over Frame Relay Voice over ATM Voice over HDLC Video Support Universal Broadband Features
Quality of Service Solutions Configuration Guide1 Quality of Service Solutions Command Reference1	Classification Scheduling Packet Drop Traffic Shaping ATM QoS SNA QoS Line Protocols
Cisco IOS Software Command Summary Dial Solutions Quick Configuration Guide System Error Messages Debug Command Reference

1This book is available in January 1999.

Service and Support

For service and support for a product purchased from a reseller, contact the reseller. Resellers offer a wide variety of Cisco  service and support programs, which are described in the section "Service and Support" in the information packet that shipped with your product.

For service and support for a product purchased directly from Cisco, use CCO.

Software Configuration Tips on the Cisco TAC Home Page

For helpful tips on configuring Cisco products, follow this path on CCO:

Software & Support: Technical Tips (button on left margin)

"Hot Tips" are popular tips and hints gathered from Cisco's Technical Assistance Center (TAC). Most of these documents are also available from the TAC's Fax-on-Demand service. To access Fax-on-Demand and receive documents at your fax machine, call 888-50-CISCO (888-502-4726). From international areas, call 650-596-4408.

The following sections are provided from the Technical Tips page:

• Field Notices---Designed to provide notification of critical issues regarding Cisco products. These include problem descriptions, safety or security issues, and hardware defects.

• Hardware---Technical Tips related to specific hardware platforms.

• Internetworking Features---Tips on using and deploying Cisco IOS software features and services.

• Sample Configurations---Actual configuration examples complete with topology and annotations.

• Software Products---MultiNet & Cisco Suite 100, Network Management, Cisco IOS Software Bulletins, CiscoPro Configurations.

• Special Collections---Other Helpful Documents: Frequently Asked Questions, Security Advisories, References & RFCs, Case Studies, CiscoPro Documentation CD-ROM.

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 Cisco's 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 package, which ships with your product. The Documentation CD-ROM, a member of the Cisco Connection Family, is updated monthly. Therefore, it might be more current than printed documentation. To order additional copies of the Documentation CD-ROM, contact your local sales representative or call customer service. The CD-ROM package is available as a single package 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.

If you are reading Cisco product documentation on the World Wide Web, you can submit comments electronically. Click Feedback in the toolbar and select Documentation. After you complete the form, click Submit to send it to Cisco. We appreciate your comments.

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