Table Of Contents
Release Notes for Cisco
800 Series Routers for
Cisco IOS Release 12.0(1)XBCisco IOS Feature Sets for Cisco 800 Series Routers
Automatic Detection of ISDN Switch and SPIDs
Excessive ISDN Line Activation
Phone Mate Answering Machine Model 9200
Cisco IOS Software Documentation
Software Configuration Tips on the Cisco TAC Home Page
Release Notes for Cisco
800 Series Routers for
Cisco IOS Release 12.0(1)XB
March 2, 1999
These release notes describe the new features and significant software components for Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1 for Cisco 800 series routers.
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The Cisco 800 series routers support a subset of the Cisco IOS features described in these release notes. The Cisco IOS features that are available for the Cisco 800 series routers are listed in the section "Cisco IOS Feature Sets for Cisco 800 Series Routers" on page 3.
Contents
These release notes discuss the following topics:
System Requirements
This section describes the system requirements and includes the following sections:
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Memory Requirements
Table 1This section describes the memory requirements for the Cisco IOS feature sets supported by Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1 on Cisco 800 series routers.
Cisco 800 Series Routers
The Cisco 800 series routers connect small professional offices over Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) lines to corporate networks and to the Internet. summarizes the Cisco 800 series routers and the ports that each model offers.
The Cisco 800 series routers provide the following key features:
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Cisco IOS Feature Sets for Cisco 800 Series Routers
The following list shows which feature sets are supported on the Cisco 800 series routers. These feature sets only apply to Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1:
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Feature Set Tables
To determine what features are available with each feature set (software image), see . The table summarizes the features you can use when running a specific feature set on the Cisco 800 series routers. The feature set table uses the following symbol conventions to identify features:
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The Cisco 800 series routers also support the features listed in Table 4.
Table 4 Additional Features supported by Cisco 800 Routers
New and Changed Information
The following sections list the new features supported by the Cisco 800 series routers in Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1.
New Software Features
The following new features in Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1 are available for the Cisco 800 series routers. These Cisco IOS releases also support the features in Cisco IOS Release 12.0(1)T, which are described in the Release Notes for Cisco IOS Release 12.0T. To access this document, see the "Related Documentation" section later in this document.
Voice Features Over ISDN
The Cisco 800 series routers support the connection of analog telephones, fax machines, and modems. These devices are connected to basic telephone services through the ISDN line. The routers support the following supplementary services, which can be ordered from the telephone service provider:
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The ISDN voice priority feature controls the priority of data and voice calls for the devices connected to the router telephone ports. If an ISDN circuit endpoint is busy with a data call or calls, and either a voice call comes in or you attempt to place a voice call, the data call is handled per the voice priority setting.
Automatic Detection of ISDN Switch and SPIDs
This feature applies to North America only. The Cisco 800 series routers can detect the ISDN switch that supports the ISDN line and the service profile identifiers (SPIDs) assigned by the telephone service provider. SPIDs identify the ISDN B channels. The SPID format is generally an ISDN telephone number with numbers added to it, for example, 40855522220101. Depending on the switch that supports the ISDN line, the ISDN line could be assigned zero, one, or two SPIDs.
Important Notes
This section describes warnings and cautions about using the Cisco IOS Release 12.0(1)XB software.
B Channel Activation
When a call comes in, a B channel is activated. If the amount of traffic on the B channel exceeds a threshold, the other B channel is activated. If the amount of traffic falls below the threshold, one of the B channels is deactivated. The B channel that is initially activated when the call comes in is not necessarily B1 nor is the B channel that is deactivated when the traffic level lessens necessarily B2.
Dial Peer Limitation
The isdn answer1 and isdn answer2 commands determine which called telephone numbers, for example, 555-1111 and 555-2222, a Cisco 800 series router can answer. Using these commands limits a router to using the two dial peers that contain the telephone numbers 555-1111 and 555-2222. (When not using these commands, a router can use up to six dial peers.)
A sample scenario in which the isdn answer1 and isdn answer2 commands are used is when a Cisco 801 or Cisco 803 router is connected with other ISDN devices to an ISDN S-bus.
Excessive ISDN Line Activation
The following protocols send updates that can cause an ISDN line to be activated excessively thereby increasing your monthly ISDN line cost:
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For information on preventing this situation, refer to the Cisco 800 Series Routers Software Configuration Guide. This guide contains information on setting up extended access lists to prevent IP, UDP, IPX, and SNTP updates from activating the ISDN line. For CDP, make certain that you enter the no cdp enable command to disable CDP.
Phone Mate Answering Machine Model 9200
Phone Mate answering machine model 9200 failed to recognize the ringing signal sent by AMD R79 ringing SLIC. This was confirmed by testing against Phone Mate model 3750 and newer model 9300.
Open Caveats
This section describes possibly unexpected behavior by Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1. This section describes only severity 1 and 2 caveats.
In addition, some caveats in Cisco IOS Releases 12.0(1) T apply to Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1. For descriptions of Cisco IOS Release 12.0 T caveats, see the Cisco IOS Software Release 12.0 T Caveats. To access this document, see the section, "Related Documentation."
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For example, the following sequence of events causes a failure:
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no shutisdn spid1 0 4081234567isdn spid2 0 4081234568isdn autodetectThe proper sequence of events is as follows:
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isdn spid1 0 4081234567isdn spid2 0 4081234568isdn autodetect[CSCdk44854]•
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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 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 inIt 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. [CSCdk77426]
Related Documentation
The following sections describe the documentation available for the Cisco 800 series routers. Typically these documents consist of hardware installation guides, software installation guide 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 on the latest Documentation CD-ROM. These electronic documents might contain updates and modifications made after the paper documents were printed. For information on CCO, refer to the "Cisco Connection Online" section later in this document. For more information on to the CD-ROM, refer to the "Documentation CD-ROM" section later in this document.
The following sections describe the documentation related to these release notes:
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Cisco IOS Software Documentation
The release notes for Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1 should be used in conjunction with the Release Notes for Cisco IOS Release 12.0 T. This document describes the release from which the current special release is derived.
Additional documentation for Cisco IOS Release 12.0 T is listed below.
To access release-specific documentation on the documentation CD-ROM, follow this path:
Cisco Product Documentation: Cisco Product Documentation/Cisco IOS Software Configuration/Cisco IOS Release 12.0
The following documents apply to Cisco IOS Releases 12.0(1)XB and 12.0(1)XB1:
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Platform-Specific Documents
Hardware documentation for the Cisco 800 series routers is listed below. These documents ship with the Cisco 800 series routers.
To access hardware documents on CCO, follow this path:
Products and Ordering: Cisco Documentation: Cisco Product Documentation/Access Servers and Access Routers/Fixed Access Routers/Cisco 800
To access hardware documentation on the documentation CD-ROM, follow this path:
Cisco Product Documentation: Cisco Product Documentation/Access Servers and Access Routers/Fixed Access Routers/Cisco 800
The following documents are specific to the Cisco 800 series routers:
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Software Documents
Cisco IOS software documentation is listed in . Software documentation consists of the Cisco IOS configuration guides and command references and also includes several supporting documents. These documents are shipped with the Cisco 800 series routers in electronic form on the Documentation CD-ROM, unless you specifically ordered the printed version of the documents.
To access software documents on CCO, follow this path:
Products and Ordering: Cisco Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0
To access software documentation on the documentation CD-ROM, follow this path:
Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.0
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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.
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For service and support for a product purchased directly from Cisco, use CCO.
Software Configuration Tips on the Cisco TAC Home Page
The following URL contains links to access helpful tips on configuring your Cisco products:
http://www.cisco.com/kobayashi/serv_tips.shtml
This URL is subject to change without notice. If it changes, point your web browser to http://www.cisco.com/, and follow this path: Software & Support, Technical Tips (button on left margin).
"Hot Tips" are popular tips and hints gathered from the Cisco Technical Assistance Center (TAC). Most of these documents are available from the TAC fax-on-demand service. To access fax-on-demand and receive documents at your fax machine from the USA, call 888-50-CISCO (888-502-4726). From other areas, call 415-596-4408.
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 access 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.
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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, select Documentation, and click Enter the feedback form. After you complete the form, click Submit to send it to Cisco. We appreciate your comments.
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