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Table Of Contents
Release Notes for Cisco AS5300 Universal Access Server/Voice Gateway for Cisco IOS Release 12.0 XH
Determining the Software Version
Upgrading to a New Software Release
New Features in Release 12.0(4)XH4
Single Density Voice Support with DSPM-542
High Density Voice Support with DSPM-549
Open Settlements Protocol (OSP) for IP Telephony
Debit Card Accounting and New RADIUS Attributes for IP Telephony
Interactive Voice Response (IVR)
Deprecated and Replacement MIBs
Caveat CSCdr91706 and IOS HTTP Vulnerability
Frame Relay/HDLC/PPP Encapsulation and Backhaul of VoIP Traffic
Encryption Limitation on Open Settlements Protocol (OSP) for IP Telephony
DSPM-542 and DSPM-549 Restrictions
Affected Devices and Software Versions
Open Caveats—Release 12.0(4)XH4
Resolved Caveats—Release 12.0(4)XH4
Cisco IOS Software Documentation Set
Release 12.0 Documentation Set
Software Configuration Tips on the
Cisco Technical Assistance Center Home Page
Release Notes for Cisco AS5300 Universal Access Server/Voice Gateway for Cisco IOS Release 12.0 XH
December 1, 2000
These release notes for the Cisco AS5300 universal access server/Voice Gateway support Cisco IOS Release 12.0 XH, up to and including Release 12.0(4)XH4. These release notes are updated as needed to describe new features, memory requirements, hardware support, software platform deferrals, and changes to the microcode or modem code and related documents.
For a list of the software caveats that apply to Release 12.0(4)XH4, see the "Caveats" section and Caveats for Release 12.0 T . The caveats document is updated for every maintenance release and is located on Cisco Connection Online (CCO) and the Documentation CD-ROM.
Use these release notes with Cross-Platform Release Notes for Cisco IOS Release 12.0 on CCO and the Documentation CD-ROM.
Contents
These release notes describe the following topics:
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MIBs
Introduction
This section contains information about the Cisco AS5300 universal access server/Voice Gateway and Early Deployment (ED) releases for the Cisco AS5300.
Note
The Cisco AS5300 is a versatile data communications platform that performs two functions in a single modular chassis depending on the installed feature cards and IOS images:
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The remote access server is intended for Internet service providers (ISPs), telecommunications carriers, and other service providers that offer managed Internet connections, as well as medium to large sites that provide both digital and analog access to users on an enterprise network. By terminating both analog and digital calls on the same chassis simultaneously, the access server provides a clear, simple, and easy migration path from analog dial access services to digital dial access services.
The Cisco AS5300/Voice Gateway is a versatile data communications platform that provides the functions of an access server, router, and digital modem(s) in a single modular chassis. The AS5300 includes three feature card slots: one holds a T1/E1/PRI feature card, and the other two support modem feature cards or voice digital signal processor (DSP) feature cards. When equipped with modem cards, the AS5300 serves as a remote access concentrator for dial-up (modem or ISDN) Internet access. When equipped with voice feature cards and Voice IOS, the AS5300/Voice Gateway serves as a voice (VoIP) gateway. By using one slot for modems and the other for voice DSPs, the AS5300 can serve in both capacities. Modem, voice, or fax calls are routed to the appropriate cards/resources via Dialed Number Identification Service (DNIS).
For information on new features and Cisco IOS commands supported by Release 12.0 XH, see the "New and Changed Information" section and the "Related Documentation" section.
Early Deployment Releases
These release notes describe only Release 12.0 XH for Cisco AS5300 universal access server/Voice Gateway and do not describe features that are available in Release 12.0 or other Release 12.0 Early Deployment (ED) releases. Release 12.0 XH is an Early Deployment (ED) release based on Release 12.0 and announces fixes to software caveats and support for new Cisco hardware.
For information about features in Release 12.0, see Cross-Platform Release Notes for Cisco IOS Release 12.0 on CCO and the Documentation CD-ROM.
For information about features in 12.0 XH ED releases, see .
For information about features in other platforms, see Release Notes for Cisco IOS Release 12.0 on CCO and the Documentation CD-ROM.
System Requirements
This section describes the system requirements for Release 12.0(4)XH4:
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Memory Recommendations
Table 2 describes the memory recommendations for the Cisco AS5300 platform feature sets supported by Cisco IOS Release 12.0(4)XH4.
Hardware Supported
Cisco IOS Release 12.0 XH supports the Cisco AS5300 universal access server/Voice Gateway. For detailed descriptions of the new hardware features, see the "New and Changed Information" section.
Determining the Software Version
To determine the version of Cisco IOS software running on your Cisco AS5300, log in to the Cisco AS5300 and enter the show version EXEC command:
router>show versionCisco Internetwork Operating System SoftwareIOS (tm) AS5300 Software c5300-js-mz, Version 12.0(4)XH4, RELEASE SOFTWAREUpgrading to a New Software Release
For information on upgrading to a new software release, see the product bulletin Cisco IOS Software Release 12.0 T Upgrade Paths and Packaging Simplification (#819: 1/99) on CCO at:
Service & Support: Product Bulletins: Software
Under Cisco IOS 12.0, click Cisco IOS Software Release 12.0 T Upgrade (#819: 1/99).
VCWare Requirements
Use the Cisco AS5300 universal access server/Voice Gateway in Cisco IOS Release 12.0(4)XH4 with VCWare Version 4.09/4.10. Previous versions will not work. Please refer to the Release Notes for Cisco VCWare Version 4.10 for Cisco AS5300/Voice Gateway Feature Cards.
Note
Modem Code Software
Modem code is either stored in Flash memory or bundled in the Cisco IOS software image. Bundling eliminates the need to store separate modem code images. When the Cisco AS5300 is powered on, the system software unpacks the modem code and loads the proper code on the modem cards.
Note
The modem code release notes are on CCO and the Documentation CD-ROM:
You can reach the release notes on CCO at:
Technical Documents: Documentation Home Page: Access Servers and Access Routers: Firmware and Portware Information
You can reach the release notes on the Documentation CD-ROM at:
Cisco Product Documentation: Access Servers and Access Routers: Firmware and Portware Information
Feature Set Tables
The Cisco IOS software is packaged in feature sets consisting of software images—depending on the platform. Each feature set contains a specific set of Cisco IOS features.
Release 12.0(4)XH4 supports the same feature sets as Release 12.0(4)T, but Release 12.0(4)XH4 can include new features supported by the Cisco AS5300 universal access server/Voice Gateway.
CautionCisco IOS images with strong encryption (including, but not limited to 168-bit (3DES) data encryption feature sets) are subject to United States government export controls and have limited distribution. Strong encryption images to be installed outside the United States are likely to require an export license. Customer orders may be denied or subject to delay due to United States government regulations. When applicable, purchaser/user must obtain local import and use authorizations for all encryption strengths. Please contact your sales representative or distributor for more information, or send an e-mail to export@cisco.com.
lists the features and feature sets supported by the Cisco AS5300 universal access server/Voice Gateway in Cisco IOS Release 12.0 XH and uses the following conventions:
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Note
Table 5 Selected Features Supported by the Cisco AS5300
PlusAPPN High-Performance Routing
No
No
No
APPN MIB Enhancements
No
No
No
APPN over Ethernet LAN Emulation
No
No
No
APPN Scalability Enhancements
No
No
No
Bisync Enhancements:
–
–
–
Yes
Yes
Yes
Cisco MultiPath Channel (CMPC)
No
No
No
DLSw+ Enhancements:
–
–
–
–
–
–
–
Yes
Yes
Yes
FRAS Enhancements:
–
–
–
–
–
–
Yes
Yes
Yes
RIF Passthru in DLSw+
Yes
Yes
Yes
TN3270 LU Nailing
No
No
No
TN3270 Server Enhancements
No
No
No
Token Ring LANE
No
No
No
Tunneling of Asynchronous Security Protocols
Yes
Yes
Yes
DRP Server Agent
Yes
Yes
Yes
DRP Server Agent Enhancements
Yes
Yes
Yes
Voice over IP
(3)
Yes
Yes
Yes
Easy IP (Phase 1)
Yes
Yes
Yes
Easy IP (Phase 2) DHCP Server
(1)
Yes
Yes
Yes
Hot Standby Router Protocol (HSRP) over ISL in Virtual LAN Configurations
No
Yes
Yes
IP Enhanced IGRP Route Authentication
(1)
Yes
Yes
Yes
PIM Version 2
(1)
Yes
Yes
Yes
TCP Enhancements:
–
–
(1)
Yes
Yes
Yes
AppleTalk Access List Enhancements
No
Yes
Yes
DECnet Accounting
No
Yes
Yes
IPX Named Access Lists
No
Yes
Yes
IPX SAP-after-RIP
No
Yes
Yes
NLSP Enhancements
No
Yes
Yes
NLSP Multicast Support
No
Yes
Yes
Cisco Call History MIB Command-Line Interface
(1)
Yes
Yes
Yes
Cisco IOS Internationalization
(1)
Yes
Yes
Yes
Entity MIB, Phase 1
(1)
Yes
Yes
Yes
Process MIB
(3)
Yes
Yes
Yes
ISDN MIB RFC 2127
(1)
Yes
Yes
Yes
SNMPv2C
(1)
Yes
Yes
Yes
SNMPv3
(3)
Yes
Yes
Yes
SNMP Inform Requests
No
Yes
Yes
Time-Based Access Lists
(1)
Yes
Yes
Yes
Virtual Profiles
(1)
Yes
Yes
Yes
VPDN MIB
(1)
Yes
Yes
Yes
VPDN MIB and Syslog Facility
Yes
Yes
Yes
IP Multicast Load Splitting across Equal-Cost Paths
(1)
Yes
Yes
Yes
IP Multicast over ATM Point-to-Multipoint Virtual Circuits
(1)
No
No
No
PIM Version 2
(1)
Yes
Yes
Yes
IP Multicast over Token Ring LANs
(1)
Yes
Yes
Yes
Stub IP Multicast Routing
(1)
Yes
Yes
Yes
CLI String Search
(1)
Yes
Yes
Yes
RTP Header Compression
Yes
Yes
Yes
BERT/TDM
(3)
Yes
Yes
Yes
Automated Double Authentication
Yes
Yes
Yes
Certificate Authority Interoperability
No
No
Yes
Double Authentication
(1)
Yes
Yes
Yes
Encrypted Kerberized Telnet
No
No
Yes
HTTP Security
(1)
Yes
Yes
Yes
Internet Key Exchange Security Protocol
No
No
Yes
IPSec Network Security
No
No
Yes
IPSec with Triple-DES
(2)
No
No
No
MS-CHAP Support
No
Yes
Yes
Named Method Lists for AAA Authentication and Accounting
Yes
Yes
Yes
Per-User Configuration
(1)
Yes
Yes
Yes
Reflexive Access Lists
(1)
Yes
Yes
Yes
TCP Intercept
No
Yes
Yes
Vendor-Proprietary RADIUS Attributes
(1)
Yes
Yes
Yes
Vendor-Proprietary RADIUS —Additional Attributes
Yes
Yes
Yes
AppleTalk Routing over ISL and IEEE 802.10 in Virtual LANs
No
Yes
Yes
CLNS and DECnet Fast Switching over PPP
No
Yes
Yes
DECnet/VINES/XNS over ISL:
–
–
–
No
Yes
No
Fast-Switched Policy Routing
(1)
Yes
Yes
Yes
IPX Routing over ISL Virtual LANs
No
Yes
Yes
VIP Distributed Switching Support for IP Encapsulated in ISL
No
No
No
Telnet Extensions for Dialout
Yes
Yes
Yes
Virtual Templates for Protocol Translation
No
Yes
Yes
SS7/CCS7 Dial Access Solution (DAS)
(3)
Yes
Yes
Yes
Large Scale Dialout
(3)
Yes
Yes
Yes
ATM MIB Enhancements
No
No
No
PAD Enhancements
No
Yes
Yes
PAD Subaddressing
(1)
Yes
Yes
Yes
Always On/Dynamic ISDN (AO/DI)
No
Yes
Yes
Bandwidth Allocation Control Protocol
(1)
Yes
Yes
Yes
Dialer Watch
Yes
Yes
Yes
Dynamic Multiple Encaps for Dial-in over ISDN
(4)
Yes
Yes
Yes
E1 R2 Country Support1
(3)
Yes
Yes
Yes
E1 R1 Support for only Taiwan2
(3)
Yes
Yes
Yes
Enhanced Local Management Interface (ELMI)
Yes
Yes
Yes
Frame Relay Enhancements
(1)
Yes
Yes
Yes
Frame Relay MIB Extensions
(1)
Yes
Yes
Yes
Frame Relay Router ForeSight
(1)
Yes
Yes
Yes
ISDN Advice of Charge
(1)
Yes
Yes
Yes
ISDN Caller ID Callback
(1)
Yes
Yes
Yes
ISDN LAPB-TA
(4)
Yes
Yes
Yes
ISDN NFAS
(1)
Yes
Yes
Yes
Layer 2 Forwarding—Fast Switching
(1)
Yes
Yes
Yes
Leased-Line ISDN at 128 kbps
No
No
No
Microsoft Point-to-Point Compression (MPPC)
Yes
Yes
Yes
MS Callback
(1)
Yes
Yes
Yes
Modem Management Enhancements
(1)
Yes
Yes
Yes
Multiple ISDN Switch Types
Yes
Yes
Yes
National ISDN Switch Types for BRI and PRI Interfaces (NI2)
Yes
Yes
Yes
PPP over ATM
No
No
No
Stackable Home Gateway
Yes
Yes
Yes
Switched 56K Digital Connections
Yes
Yes
Yes
Telnet Extensions for Dialout
Yes
Yes
Yes
X.25 Enhancements
(1)
Yes
Yes
Yes
X.25 on ISDN
(1)
Yes
Yes
Yes
X.25 Switching between PVCs and SVCs
Yes
Yes
Yes
X.28 Emulation
Yes
Yes
Yes
CNS Client for IOS
(4)
Yes
Yes
Yes
Debit Card for Packet Telephony
(4)XH
Yes
Yes
Yes
H.323 Version 2 Support
(4)XH
Yes
Yes
Yes
High Density Voice Support with DSPM-549
(4)XH
Yes
Yes
Yes
Interactive Voice Response (IVR)
(4)XH
Yes
Yes
Yes
Service Provider 1.0 Features
(3)
Yes
Yes
Yes
Open Settlements Protocol (OSP) for IP Telephony
(4)XH
No
No
Yes
Single Density Voice Support with DSPM-542
(4)XH
Yes
Yes
Yes
TDM Hairpinning
(4)
Yes
Yes
Yes
1 E1 R2 country support requires specific versions of Mica portware. For details, see the Mica portware release notes, which are available on CCO in the Software Center. Note that country support varies with the portware release level, and the release notes provide a list of countries.
2 E1 R1 signaling support for Taiwan requires MICA portware version 2.3.1.0.
New and Changed Information
The following sections list the new hardware and software features supported by the Cisco AS5300 universal access server/Voice Gateway for Release 12.0 XH.
New Features in Release 12.0(4)XH4
H.323 Version 2 Support
H.323 Version 2 Support upgrades Cisco IOS software to comply with the mandatory requirements in the version 2 specification. This upgrade enhances the existing Voice Over IP GateWay, the Multimedia Conference Manager (GateKeeper and Proxy), and the dual tone multifrequency (DTMF) digital relay using H.245.
H.323 Version 2 defines a lightweight registration procedure that requires full registration for initial registration, but uses an abbreviated renewal procedure to update the gatekeeper and minimize overhead. Lightweight registration requires each endpoint to specify a TimeToLive (TTL) value in its Registration Request (RRQ) message.
The H.323 version 2 gateway supports the registration of fully-qualified E.164 numbers with the gatekeeper for phones connected directly to the gateway. Tunneling through H.225 User-to-User Information Element (UUIE) facilitates transparent handling of supplementary services between two endpoints through a VoIP network. This eliminates the need to interpret various supplementary signaling messages in the VoIP gateways.
Single Density Voice Support with DSPM-542
This feature implements voice support on the Cisco AS5300 using DSPM-542 digital signal processor (DSP) modules.
The benefits of voice features include:
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This release supports a C542 based VCWare that provides codec and feature interoperability between earlier generation, TI-C542 based AS5300/Voice Gateways, and the latest High Density versions. This release supports parallel C542 based VCWare/DSPWare and C549 based VCWare/DSPWare. However, note that the C542-based VCWare does not increase the number of calls supported on those earlier generation voice feature cards. Increasing support to 96/120 channels requires the latest generation (C549-based, AS53-VOXD based) voice feature cards.
High Density Voice Support with DSPM-549
This release implements high-density voice support on the Cisco AS5300 by using DSPM-549 digital signal processor (DSP) modules. When equipped with Voice Feature Cards (VFCs) and voice-enabled Cisco IOS software, the AS5300/Voice Gateway supports carrier-class VoIP and FAX over IP services.
High-density voice support increases the voice capacity of a Cisco AS5300 up to 120 channels. This increase in voice support provides the voice density of up to four T1 lines (96 voice or FAX calls) or four E1 lines (120 voice or FAX calls).
A fully configured AS5300/Voice Gateway can support up to two high density (48/60 channel) voice feature cards, and therefore the system supports up to 96/120 simultaneous voice/fax calls (4T1/E1 density).
The benefits of high-density voice features include:
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Open Settlements Protocol (OSP) for IP Telephony
Internet voice telephony is often used for toll bypass by using an existing data network or the internet instead of PSTN trunking. Calls of this nature require an originating and terminating gateway to be completed. When the originating and terminating voice gateways are owned by 2 different carriers, settlement between these carriers is required. The Settlement for Packet Voice project implements a standardized settlement protocol which can be implemented between different vendors gateways and voice settlement servers.
The Cisco gateway based Settlement protocol interacts between carriers to create a single authentication at initialization. The authentication is the basis for the establishment of a secure communication channel between the Settlement system and the infrastructure component. This channel then allows the following three types of transactions to be handled:
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Note
Debit Card Accounting and New RADIUS Attributes for IP Telephony
The Debit Card feature gives the ability to offer calling service with the use of debit accounting to service providers. The Debit Card feature and RADIUS specific enhancements also support Vendor Specific Attributes (VSA). The Debit Card for Packet Telephony on Cisco AS5300 works in tandem with the Cisco Interactive Voice Response (IVR) feature. The IVR voice scripts have been modified to use Tool Command Language (TCL) scripts.
The feature components consist of IVR functionality in Cisco IOS software that works in connection with an integrated third-party billing system. This includes the ability to maintain per-user credit balance information via a RADIUS interface to the Cisco IOS software. When these features are implemented, the billing system and IOS software functions enable a carrier to authorize voice calls and to debit individual user accounts in real time at the edges of a voice over IP network, without requiring external service nodes.
Interactive Voice Response (IVR)
Cisco is building voice gateways to connect more traditional telephone networks to voice over IP (VoIP) networks. Customers who are installing VoIP networks often need a mechanism at the gateway to present a customized interface to the caller. The IVR feature was first made available to customers with Cisco IOS Release 11.(3)NA2, along with the Service Provider VoIP feature set. IVR with the addition of scripts using Tool Command Language (TCL) are being introduced with Cisco IOS Release 12.0(4)XH4. These TCL IVR scripts are the default scripts that must be used with the IVR application in Cisco IOS Release 12.0(4)XH4 and later releases. 12.0(4)XH4 are compatible with TCLware 1.0.x.
IVR consists of simple voice prompting and digit collection to gather caller information for authenticating the user and identifying the destination. IVR provides the ability to:
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Note
MIBs
Current MIBs
If you have an account with CCO, you can find the current list of MIBs supported by Cisco. To reach the Cisco Network Management Toolkit, go to CCO, press Login, and click to Software Center: Network Mgmt Products: Cisco Network Management Toolkit: Cisco MIB
Deprecated and Replacement MIBs
Old Cisco Management Information Bases (MIBs) will be replaced in a future release. Currently, OLD-CISCO-* MIBs are being converted into more scalable MIBs—without affecting existing Cisco IOS products or NMS applications. You can update from deprecated MIBs to the replacement MIBs as shown in :
Important Notes
The following sections contain important notes about Cisco IOS Release 12.0(4)XH4 that can apply to the Cisco AS5300 universal access server/Voice Gateway.
Caveat CSCdr91706 and IOS HTTP Vulnerability
A defect in multiple releases of Cisco IOS software will cause a Cisco router or switch to halt and reload if the IOS HTTP service is enabled, browsing to http://router-ip/anytext?/ is attempted, and the enable password is supplied when requested. This defect can be exploited to produce a denial of service (DoS) attack.
The vulnerability, identified as Cisco bug ID CSCdr91706, affects virtually all mainstream Cisco routers and switches running Cisco IOS software releases 12.0 through 12.1, inclusive. This is not the same defect as CSCdr36952.
The vulnerability has been corrected and Cisco is making fixed releases available for free to replace all affected IOS releases. Customers are urged to upgrade to releases that are not vulnerable to this defect as shown in detail below.
This vulnerability can only be exploited if the enable password is known or not set.
You are strongly encouraged to read the complete advisory, which is available at http://www.cisco.com/warp/public/707/ioshttpserverquery-pub.shtml .
Frame Relay/HDLC/PPP Encapsulation and Backhaul of VoIP Traffic
12.0(4)XH1 is the first AS5300/Voice Gateway IOS release that supports the use of serial ports or T1/E1 ports for Frame Relay/HDLC/PPP encapsulation and backhaul of VoIP traffic. In other words, all previous IOS releases limited the AS5300/Voice Gateway to passing calls between TDM (T1/E1) ports and Ethernet (10/100 Base T) ports. Therefore, previous releases only supported the use of the earlier generation 4CT1/4CE1 feature cards. Encapsulating and backhauling VoIP traffic onto Frame Relay/HDLC/PPP links required the use of a separate router on the same Ethernet network to encapsulate and pass VoIP traffic into a serial backhaul link (and vice versa).
Release 12.0(4)XH1 supports the use of the AS5300's 4CT1+ Serial port and 4CE1+ Serial port feature cards, previously only supported for AS5300 access server (modem/ISDN termination) applications. It is important to note that there are very defined limits to the use of native encapsulation and backhaul and, in fact it is strongly recommended that dedicated routers (such as Cisco 3600, 7200, 7500) be dedicated to backhaul of VoIP traffic via Frame Relay/HDLC/PPP links. Voice quality is directly affected by latency, and CPU load and as a result, this section highlights some key requirements and limitations associated with use of native FR/HDLC/PPP encapsulation for voice applications using the AS5300/Voice Gateway.
Summary Highlights of Operational Limits with Backhaul/Encapsulation Enabled:
In order to maintain high performance, including low latency (less than 200 ms round trip delay), high call success rate (99% CSR), and optimal voice quality, Cisco only supports use of native FR/HDLC/PPP encapsulation given the following conditions/caveats:
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And even in the case of a very low expected call volume, a simulation of the proposed network environment should first be tested to validate achievable call success rate, low latency with CRTP enabled. If native CRTP is deemed necessary, Call rate should be limited to 0.5 calls/sec (1 call every 2 secs).
These caveats are provided for guidance, and there are a wide variety of other backhaul scenarios that may be well supported by the AS5300/Voice Gateway, particularly for low volume applications. When considering other configurations, bear in mind that there are many other VoIP features, processes, and conditions that contribute to system load, including call volume, H.323 RAS transactions, AAA/RADIUS negotiation, SNMP polling, IVR, Open Settlements Protocol transactions, enabling debugs (including "show" commands), etc. This section is provided as a result of extensive characterization testing performed on the AS5300/Voice Gateway while a variety of previously mentioned capabilities were enabled.
Encryption Limitation on Open Settlements Protocol (OSP) for IP Telephony
Open Settlements Protocol (OSP) for IP Telephony is offered only in crypto images; they are under export controls. All users must be entitled before they can receive 56 or 56i images. You (and your customers) can entitle yourselves by filling out the forms located at the following URL:
http://www.cisco.com/kobayashi/library/12.0
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"Apply for Cisco IOS Cryptographic Software under export licensing controls"
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"Download Cisco IOS cryptographic software under export licensing controls"
Once you are entitled, you will be able to see crypto images in the upgrade planner. Also, once you are entitled, you do not have to entitle yourself again, unless you are coming from a different host. You do not have to entitle yourself for every release because entitlement is good for all releases.
DSPM-542 and DSPM-549 Restrictions
The following restrictions apply to the DSPM-542 and/or DSPM-549.
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The DSPM-542 uses the AS53-6VOX DSP module with one of the following configurations:
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Cisco IOS Syslog Failure
Certain versions of Cisco IOS software can fail when they receive invalid User Datagram Protocol (UDP) packets sent to their syslog ports (port 514). At least one commonly used Internet scanning tool generates packets that cause such problems. This fact has been published on public Internet mailing lists, which are widely read both by security professionals and by security crackers. This information should be considered in the public domain.
Attackers can cause Cisco IOS devices to repeatedly fail and reload, resulting in a completely disabled Cisco IOS device that needs to be reconfigured by its administrator. Some Cisco IOS devices can hang instead of failing when attacked. These devices do not recover until they are manually restarted by reset or power cycling. An administrator must visit the device to restart it, even if the attacker is no longer actively sending any traffic. Some devices have failed without providing stack traces; some devices indicate that they were "restarted by power-on," even when that was not the case.
Assume that any potential attacker knows the existence of this problem and the ways to exploit it. An attacker can use tools available to the public on the Internet and does not need to write any software to exploit the vulnerability. Minimal skill is required and no special equipment is required.
Despite Cisco specifically inviting such reports, Cisco has received no actual reports of malicious exploitation of this problem.
This vulnerability notice was posted on Cisco's World Wide Web site:
http://www.cisco.com/warp/public/770/iossyslog-pub.shtml
This information was also sent to the following e-mail and USENET news recipients:
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Affected Devices and Software Versions
describes hardware and software that are affected by this problem. Affected versions include Releases 11.3 AA, 11.3 DB, and all 12.0 versions (including 12.0 mainline, 12.0 S, 12.0 T, and any other regular released version whose number starts with 12.0), up to the repaired releases listed in . Cisco is correcting the problem in certain special releases, will correct it in future maintenance and interim releases, and intends to provide fixes for all affected IOS variants. See , for details.
No particular configuration is needed to make a Cisco IOS device vulnerable. It is possible to filter out attack traffic by using access lists. See the "Workarounds" section for techniques. However, except at Internet firewalls, the appropriate filters are not common in customer configurations. Carefully evaluate your configuration before assuming that any filtering you have protects you against this attack.
The most commonly used or asked-about products are listed below. If you are unsure whether your device is running Cisco IOS software, log in to the device and enter the show version command. Cisco IOS software will identify itself simply as "IOS" or "Internetwork Operating System Software." Other Cisco devices do not have the show version command and identify themselves differently in their output. The most common Cisco devices that run Cisco IOS software include the following:
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Affected software versions, which are relatively new, are not necessarily available on every device listed above. If you are not running Cisco IOS software, you are not affected by this problem.
The following Cisco devices are not affected:
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This vulnerability has been assigned Cisco bug ID CSCdk77426.
Solution
Cisco offers free software updates to correct this vulnerability for all affected customers—regardless of their contract status. However, because this vulnerability information has been disseminated by third parties, Cisco has released this notice before updates are available for all software versions. gives Cisco's projected fix dates.
Make sure that your hardware has adequate RAM to support the new software before installing it. The amount of RAM is seldom a problem when you upgrade within a major release, for example, from 11.2[11]P to 11.2[17]P, but it is often a factor when you upgrade between major releases, for example, from 11.2 P to 11.3 T.
Because fixes will be available for all affected releases, this vulnerability will rarely, if ever, require you to upgrade to a new major release. Cisco recommends that you carefully plan for any upgrade between major releases. Make certain no known bugs will prevent the new software from working properly in your environment.
Further upgrade planning assistance is available on Cisco's World Wide Web site at:
http://www.cisco.com
If you have service contracts, you can obtain new software through your regular update channels (generally through Cisco's World Wide Web site). You can upgrade to any software release, but you must remain within the boundaries of the feature sets you have purchased.
If you do not have service contracts, you can upgrade to only obtain the bug fixes; free upgrades are restricted to the minimum upgrade required to resolve the defects. You can only upgrade to the software described in one row of —except when no upgrade within the same row is available in a timely manner.
Obtain updates by contacting one of the following Cisco Technical Assistance Centers (TACs):
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Give the URL of this notice (http://www.cisco.com/warp/public/770/iossyslog-pub.shtml) as evidence for a free update. Customers with no contracts must request for free updates through the TAC. For software updates, please do not contact either "psirt@cisco.com" or "security-alert@cisco.com".
Workarounds
You can work around this vulnerability by preventing any affected Cisco IOS device from receiving or processing UDP datagrams addressed to port 514. You can do this by 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, apply it to all interfaces to which attackers can send datagrams. Interfaces include not only physical LAN and WAN interfaces but also virtual subinterfaces of those physical interfaces—as well as virtual interfaces and interface templates corresponding to GRE, L2TP, L2F, and other tunneling protocols.
The input access list must block traffic destined for UDP port 514 at any of the Cisco IOS device's own IP addresses—as well as at any broadcast or multicast addresses on which the Cisco IOS device may be listening. Be sure to block both old-style "all-zeros" broadcasts and new-style "all-ones" broadcasts. It is not necessary to block traffic being forwarded to other hosts—only traffic actually addressed to the Cisco IOS device.
No single input access list works in all configurations. Be sure you know the effect of your access list in your specific configuration before activating it.
The following example shows a possible access list for a three-interface router, along with the configuration commands needed to apply the list. The example assumes input filtering is not needed—other than as a workaround for this problem:
! Deny all multicasts, and all unspecified-net broadcasts, to port 514access-list 101 deny udp any 224.0.0.0 31.255.255.255 eq 514! Deny old-style unspecified-net broadcastsaccess-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 514access-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 514access-list 101 deny udp any host 172.16.2.1 eq 514access-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 interfaceinterface ethernet 0ip address 172.16.1.1 255.255.255.0ip access-group 101 ininterface ethernet 2ip address 172.16.2.1 255.255.255.0ip access-group 101 ininterface ethernet 3ip address 172.16.3.3 255.255.255.0ip access-group 101 inListing all possible addresses—especially all possible broadcast addresses—to which attack packets can be sent is complicated. If you do not need to forward any legitimate syslog traffic received on an interface, you can block all syslog traffic arriving on that interface. Remember that blocking will affect traffic routed through the Cisco IOS device—as well as traffic destined to the device. If the IOS device is expected to forward syslog packets, you will have to filter in detail. Because input access lists impact system performance, install them with caution—especially on systems running very near their capacity.
Software Versions and Fixes
Many Cisco software images have been or will be specially reissued to correct this vulnerability. For example, regular released Cisco IOS version 12.0(2) is vulnerable, as are interim versions 12.0(2.1) to 12.0(2.3). The first fixed interim version of Release12.0 mainline software is Release12.0(2.4). However, a special release, 12.0(2a), contains only the fix for this vulnerability and does not include any other bug fixes from later 12.0 interim releases.
If you are running Release 12.0(2) and want to fix this problem without risking possible instability presented by installing the 12.0(2.4) interim release, you can upgrade to Release 12.0(2a). Release 12.0(2a) is a "code branch" from the Release 12.0(2) base, which will merge back into the Release 12.0 mainline at Release 12.0(2.4).
Special releases, like 12.0(2a), are one-time spot fixes, and they will not be maintained. Thus, the upgrade path from Release 12.0(2a) is to Release 12.0(3).
Note
Table 7 Affected and Repaired Software Versions
11.2 and earlier releases—all variants
Unaffected early releases (no syslog server)
Unaffected
Unaffected
Unaffected
11.3, 11.3 T, 11.3 DA, 11.3 MA, 11.3 NA, 11.3 WA, 11.3(2)XA
11.3 releases without syslog servers
Unaffected
Unaffected
Unaffected
11.3 AA
11.3 early deployment for AS58xx
11.3(7)AA2, 8-JAN-19994
11.3(7.2)AA
11.3(8)AA, 15-FEB-1999
11.3 DB
11.3 for Cisco NRP routing blade in Cisco 6400 xDSL DSLAM
11.3(7)DB2, 18-JAN-1999
12.0
12.0 Mainline
12.0(2a), 8-JAN-1999
12.0(2.4)
12.0(3), 1-FEB-1999
12.0 T
12.0 new technology early deployment
12.0(2a)T1, 11-JAN-1999
12.0(2.4)T
12.0(3)T, 15-FEB-1999
12.0 S
ISP support; 7200, RSP, GSR
12.0(2.3)S, 27-DEC-1998
12.0(2)S5 , 18-JAN-1999
12.0 DB
12.0 for Cisco 6400 universal access concentrator node switch processor (lab use)
12.0(2)DB, 18-JAN-1999
12.0(1)W
12.0 for Catalyst 8500 and LS1010
12.0(1)W5(5a) and 12.0(1a)W5(5b) (LS1010 platform only)
12.0(1)W5(5.15)
12.0(1)W5(6) (platform support for Catalyst 8540M will be in 12.0(1)W5(7))
12.0(0.6)W5
One-time early deployment for CH-OC-12 module in Catalyst 8500 series switches
Unaffected; one-time release
Unaffected
Unaffected; To upgrade use 12.0(1)W5 releases.
12.0(1)XA3
Short-life release; merged to 12/0T at 12.0(2)T
Obsolete
Merged
Upgrade to 12.0(2a)T1 or to 12.0(3)T.
12.0(1)XB
Short-life release for Cisco 800 series; merged to 12.0 T and 12.0 (3)T
12.0(1)XB1
Merged
Upgrade to 12.0(3)T.
12.0(2)XC
Short-life release for new features in Cisco 2600, Cisco 3600, uBR7200, uBR900 series; merged to 12.0 T at 12.0(3)T
12.0(2)XC1, 7-JAN-1999
Merged
Upgrade to 12.0(3)T
12.0(2)XD
Short-life release for ISDN voice features; merged to 12.0 T at 12.0(3)T
12.0(2)XD1, 18-JAN-1999
Merged
Upgrade to 12.0(3)T
12.0(1)XE
Short-life release
12.0(2)XE, 18-JAN-1999
Merged
Upgrade to 12.0(3)T
1 A special fix is a one-time release that provides the most stable immediate upgrade path.
2 Interim releases are tested less rigorously than regular maintenance releases; interim releases can contain serious bugs.
3 Fixed maintenance releases are on a long-term upgrade path. Other long-term upgrade paths also exist.
4 All dates in this table are estimates and are subject to change.
5 This entry is not a misprint. The 12.0(2.3)S interim release is available before the 12.0(2)S regular release.
Caveats
Caveats describe unexpected behavior in Cisco IOS software releases. Severity 1 caveats are the most serious caveats; severity 2 caveats are less serious.
This section only contains open and resolved caveats for the current Cisco IOS maintenance release.
All caveats in Release 12.0 and Release 12.0 T are also in Release 12.0 XH.
For information on caveats in Cisco IOS Release 12.0, see Caveats for Cisco IOS Release 12.0.
For information on caveats in Cisco IOS Release 12.0 T, see Caveats for Cisco IOS Release 12.0 T, which lists severity 1 and 2 caveats, and is located on CCO and the Documentation CD-ROM.
Note
Open Caveats—Release 12.0(4)XH4
This section describes possibly unexpected behavior by Release 12.0(4)XH4.
Miscellaneous
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The socket_recv() current does not clear the READ event under some error condition. This results in the READ event staying in the process event queue. The process will be waken up to process the even and socket_recv() would return the same error causing the process to spin in the loop. The problem was found with CCH323_CT process in some cases spin with 98% CPU. with socket read error similar to the one below:
Nov 22 19:01:45.941: process_get_socket_event(): pid 111, proc_soc 0x6226FD08 fd 3 mask 0x1 sock 0x62779184, sock->next 0x627BA000*Nov 22 19:01:46.865: process_get_socket_event(): pid 111, proc_soc 0x6226FD08 fd 3 mask 0x1 sock 0x62779184, sock->next 0x627BA000*Nov 22 19:01:46.865: SOCKET: Read failed: socket 0x62779184 can't read anymore*Nov 22 19:01:46.865: process_get_socket_event(): pid 111, proc_soc 0x6226FD08 fd 2 mask 0x1 sock 0x627BA000, sock->next 0x6260E8B8*Nov 22 19:01:46.865: SOCKET: Read failed: socket 0x627BA000 can't read anymore 3d18h: %SYS-3-MSGLOST: 47995 messages lost because of queue overflow*Nov 22 19:01:46.941: SOCKET: Read failed: socket 0x62779184 can't read anymore*Nov 22 19:01:47.869: process_get_socket_event(): pid 111, proc_soc 0x6226FD08 fd 3 mask 0x1 sock 0x62779184, sock->next 0x627BA000*Nov 22 19:01:47.873: SOCKET: Read failed: socket 0x62779184 can't read anymore*Nov 22 19:01:47.873: process_get_socket_event(): pid 111, proc_soc 0x6226FD08 fd 2 mask 0x1 sock 0x627BA000, sock->next 0x6260E8B8*Nov 22 19:01:47.873: SOCKET: Read failed: socket 0x627BA000 can't read anymoreResolved Caveats—Release 12.0(4)XH4
No resolved caveats have been reported for Release 12.0(4)XH4 at this time.
Related Documentation
The following sections describe the documentation available for the Cisco AS5300 universal access server/Voice Gateway. These documents consist of hardware and software installation guides, Cisco IOS configuration and command references, system error messages, feature modules, and other documents.
Documentation is available as printed manuals or electronic documents, except for feature modules, which are available online on CCO and the Documentation CD-ROM.
Use these release notes with these documents:
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Release-Specific Documents
The following documents are specific to Release 12.0 and are located on CCO and the Documentation CD-ROM:
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On CCO at:
Technical Documents: Documentation Home Page: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Release Notes: Cross-Platform Release Notes
On the Documentation CD-ROM at:
Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Release Notes: Cross-Platform Release Notes
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Technical Documents: Product Bulletins
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As a supplement to the caveats listed in "Caveats" in these release notes, see Caveats for Cisco IOS Release 12.0 and Caveats for Cisco IOS Release 12.0 T, which contains caveats applicable to all platforms for all maintenance releases of Release 12.0 XH.
On CCO at:
Technical Documents: Documentation Home Page: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Caveats
On the Documentation CD-ROM at:
Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Caveats
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Platform-Specific Documents
These documents are available for the Cisco AS5300 universal access server/Voice Gateway on CCO and the Documentation CD-ROM:
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On CCO at:
Technical Documents: Documentation Home Page: Access Servers and Access Routers: Access Servers: Cisco AS5300
On the Documentation CD-ROM at:
Cisco Product Documentation: Access Servers and Access Routers: Access Servers: Cisco AS5300
Feature Modules
Feature modules describe new features supported by Release 12.0 XH and are updates to the Cisco IOS documentation set. A feature module consists of a brief overview of the feature, benefits, configuration tasks, and a command reference. As updates, the feature modules are available online only. Feature module information is incorporated in the next printing of the Cisco IOS documentation set.
On CCO at:
Technical Documents: Documentation Home Page: Cisco IOS Software Configuration: Cisco IOS Release 12.0: New Feature Documentation: New Features in 12.0-Based Limited Lifetime Releases: New Features in Release 12.0 XH
On the Documentation CD-ROM at:
Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: New Feature Documentation: New Features in 12.0-Based Limited Lifetime Releases: New Features in Release 12.0 XH
Cisco IOS Software Documentation Set
The Cisco IOS software documentation set consists of the Cisco IOS configuration guides, Cisco IOS command references, and several other supporting documents, which 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, Cisco IOS software functionality, and contain comprehensive configuration examples. Chapters in a command reference provide complete command syntax information. Use each configuration guide with its corresponding command reference.
On CCO and the Documentation CD-ROM, two master hot-linked documents provide information for the Cisco IOS software documentation set.
You can reach these documents on CCO at:
Technical Documents: Documentation Home Page: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Configuration Guides and Command References
You can reach these documents on the Documentation CD-ROM at:
Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0: Configuration Guides and Command References
Release 12.0 Documentation Set
describes the contents of the Cisco IOS Release 12.0 software documentation set, which is available in electronic form and in printed form upon request.
Note
You can reach the Cisco IOS documentation set on CCO at:
Technical Documents: Documentation Home Page: Cisco IOS Software Configuration: Cisco IOS Release 12.0
You can reach the Cisco IOS documentation set on the Documentation CD-ROM at:
Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0
Note
Service and Support
For service and support for a product purchased from a reseller, contact the reseller, who offers a wide variety of Cisco service and support programs described in "Service and Support" of Cisco Information Packet shipped with your product.
Note
For service and support for a product purchased directly from Cisco, use CCO.
Software Configuration Tips on the
Cisco Technical Assistance Center Home PageIf you have a CCO login account, you can access the following URL, which contains links and tips on configuring your Cisco products:
http://www.cisco.com/kobayashi/technotes/serv_tips.shtml
This URL is subject to change without notice. If it changes, point your Web browser to CCO and click on this path: Products & Technologies: Products: Technical Tips.
The following sections are provided from the Technical Tips page:
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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 reach CCO in the following ways:
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For a copy of CCO's Frequently Asked Questions (FAQ), contact cco-help@cisco.com. For additional information, contact cco-team@cisco.com.
Note
Documentation CD-ROM
Cisco documentation and additional literature are available in a CD-ROM package, which package that 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. Translated documentation can be accessed at http://www.cisco.com/public/countries_languages.shtml.
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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