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Table Of Contents
Release Notes for Cisco uBR905 Cable Access Router for Cisco IOS Release 12.1(3a)XL2
Cisco uBR905 Cable Access Router
Determining the Software Version
Upgrading to a New Software Release
New Hardware and Software Features in Cisco IOS Release 12.1(3a) XL4
New Hardware and Software Features in Cisco IOS Release 12.1(3a) XL3
New Hardware Features in Release 12.1(3a)XL2
New Software Features in Release 12.1(3a)XL2
Cable Monitor Web Diagnostics Tool
Cisco IOS Firewall (Phase I and II)
Cisco Secure Intrusion Detection System (IDS) Support
DOCSIS Baseline Privacy Interface (BPI)
DOCSIS Baseline Privacy Management Information Base
Dynamic Host Configuration Protocol Proxy Support
Easy IP—DHCP Server and NAT/PAT
Full and DOCSIS-Compliant Bridging
HSRP Support for ICMP Redirects (CSCdp37610)
IPSec Encryption (56-bit and 3DES)
Management Information Base (MIB) Features
Secure Shell Version 1 Client Support
VPN Enhancement—Dynamic Crypto Map
DOCSIS CLI Commands are Removed
GRE IP Tunnels Are Not Supported
Upgrading Software Images Using BPI
Using Access Lists 100 and 101
Using Multiple PCs with the Cisco uBR905 Cable Access Router
Radio Frequency Interface MIBs
Open Caveats—Cisco IOS Release12.1(3a)XL4
Resolved Caveats—Cisco IOS Release12.1(3a)XL4
Open Caveats—Release 12.1(3a)XL2
Closed or Resolved Caveats—Release 12.1(3a)XL2
Cisco IOS Software Documentation Set
Release 12.1 Documentation Set
Obtaining Technical Assistance
Software Configuration Tips on the Cisco Technical Assistance Center Home Page
Release Notes for Cisco uBR905 Cable Access Router for Cisco IOS Release 12.1(3a)XL2
February 16, 2002
Part Number: OL-0633-01 Rev. E0
Note
You can find the most current Cisco IOS documentation on Cisco Connection Online (CCO). These electronic documents may contain updates and modifications made after this document was published.
These release notes for the Cisco uBR905 Cable Access Router describe the enhancements provided in Cisco IOS Release 12.1(3a)XL2. 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 software caveats that apply to Release 12.1(3a)XL2, see the "Caveats" section and Caveats for Cisco IOS Release 12.1 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 12.1 located on CCO and the Documentation CD-ROM. For complete documentation on the Cisco uBR905 Cable Access Router, see the documentation listed in the "Related Documentation" section.
Contents
These release notes describe the following topics:
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Introduction
The DOCSIS-based Cisco uBR905 Cable Access Router gives small office/home office (SOHO) and branch office subscribers high-speed Internet or Intranet access. The Cisco uBR905 Cable Access Router supports data traffic via a shared two-way cable system and Internet Protocol (IP) backbone network. The Cisco uBR905 Cable Access Router connects computers and other customer premises devices at a subscriber site to the service provider's cable, hybrid/fiber coax (HFC), and IP backbone network.
The Cisco uBR905 Cable Access Router is based on Data-over-Cable Service Interface Specifications (DOCSIS) and interoperates with any bidirectional, DOCSIS-qualified Cable Modem Termination System (CMTS). The Cisco uBR905 Cable Access Router ships from the Cisco factory with a Cisco IOS software image stored in nonvolatile Flash memory that supports DOCSIS-compliant bridging data operations. The Cisco uBR905 Cable Access Router functions as a cable modem at the subscriber site to convey data communications on the cable television system.
Note
Based on the feature licenses your company purchased, other Cisco IOS images can be downloaded from Cisco Connection Online (CCO). Special operating modes, based on your service offering and the practices in place for your network, can be supported for the Cisco uBR905 router, based on the available images in Cisco IOS Release 12.1(3a)XL2. The Cisco uBR905 Cable Access Router can also function as an advanced router, providing wide area network (WAN) data connectivity in a variety of configurations.
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Cisco uBR905 Cable Access Router
The Cisco uBR905 Cable Access Router features a single F-connector interface to the cable system, four RJ-45 (10BaseT Ethernet) hub ports, and one RJ-45 console port to connect to a laptop computer/console terminal for local Cisco IOS configuration. The Cisco uBR905 Cable Access Router also provides an onboard IPSec hardware accelerator, which provides high-performance encryption that is significantly faster than software-based encryption.
The Cisco uBR905 Cable Access Router supports a number of Cisco IOS software images. The feature sets available in Release 12.1(3a)XL2 include Easy IP, Cisco IOS Firewall (Phases I and Phase II), and IPSec encryption.
Early Deployment Releases
These release notes describe the Cisco uBR905 Cable Access Router for Cisco IOS Release 12.1 XL, which is an early deployment (ED) release based on Cisco IOS Release 12.1 T. Early deployment releases contain fixes for software caveats and support for new Cisco hardware and software features.
Table 1 shows that Release 12.1(3a)XL1 is the initial early deployment release of the Cisco uBR905 Cable Access Router:
Table 1 Early Deployment Releases for the Cisco uBR905 Cable Access Router
12.1(3a)XL1
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Now
1 SID = Service ID
2 HSRP = Hot-Standby Routing Protocol
3 ICMP = Internet Control Message Protocol
4 DES = Data Encryption Standard
5 MIB = Management Information Base
6 VPN = Virtual Private Network
System Requirements
This section describes the system requirements for Cisco IOS Release 12.1(3a)XL2:
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Memory Recommendations
Table 2 lists the memory recommendations for each of the feature sets available for the Cisco uBR905 Cable Access Router in Cisco IOS Release 12.1(3a)XL2. The image subset legend for Table 2Table 2 is as follows:
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Table 2 Memory Recommendations for the Cisco uBR905 Cable Access Router,
Release 12.1(3a)XL2 Feature Sets
Flash
Memory
DRAM
Memory
FromValue Telecommuter—Easy IP and IPSec 56
ubr925-k1sv4y556i-mz
8 MB Flash
24 MB DRAM
RAM
Performance Telecommuter— Easy IP and IPSec 3DES
ubr925-k1k2sv4y5-mz
8 MB Flash
24 MB DRAM
RAM
Value Small Office—Easy IP, FW2 , and IPSec 56
ubr925-k1o3sv4y556i-mz
8 MB Flash
24 MB DRAM
RAM
Performance Small Office— Easy IP, FW2, and IPSec 3DES
ubr925-k1k2o3sv4y5-mz
8 MB Flash
24 MB DRAM
RAM
1 The voice feature set is not supported on the Cisco uBR905 Cable Access Router.
2 FW—Cisco IOS Firewall
Headend Interoperability
DOCSIS Concatenation
If using DOCSIS concatenation with a 16-QAM (quadrature amplitude modulation) symbol rate, the CMTS must be configured for Unique Word 16 in the preamble for both short and long data burst profiles. On the Cisco uBR7200 series universal broadband routers, use the cable modulation-profile global configuration command and specify "uw16" for both the long and short modulation profiles. See caveats CSCdp76415 and CSCdp92139 on page 22 for more detail.
DOCSIS 1.0+ Extensions
Cisco IOS Release 12.1 XL images support the Cisco DOCSIS 1.0+ Extensions, which include dynamic multi-SID assignment and concatenation. To use the dynamic multi-SID and concatenation features, both the Cisco uBR905 router and the CMTS router must support them. If you are using the Cisco uBR7200 series headend equipment as the CMTS router, Cisco IOS Release 12.1(1) T or greater is required on the CMTS router to ensure that these features are activated.
To configure the Cisco uBR905 Cable Access Router to support multiple classes of service, use either the Cisco Subscriber Registration Center (CSRC) tool or the configuration file editor of your choice. DOCSIS configuration files can contain multiple classes of service (CoS) to support voice and other real-time traffic. The first CoS is used for data (and voice if no other CoS is defined), and up to three additional classes of service can be defined to give higher priority for voice and other real-time traffic.
IPSec Encryption Support
To use IPSec encryption, both the Cisco uBR905 Cable Access Router and the destination endpoint must support IPSec encryption and be configured for the same encryption policy. The endpoint is typically an IPSec gateway such as a peer router, Cisco PIX firewall, or other device that can be configured for IPSec. (The CMTS does not need to support IPSec encryption unless it is desired that the CMTS act as an IPSec gateway.)
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Hardware Supported
The Cisco uBR905 Cable Access Router contains:
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Determining the Software Version
To determine the version of Cisco IOS software running on your Cisco uBR905 Cable Access Router, log into the Cisco uBR905 Cable Access Router and enter the show version EXEC command:
For the Cisco uBR905 Cable Access Router:
router# show versionCisco Internetwork Operating System SoftwareIOS (tm) 920 Software (ubr925-k1v4y5-mz), Version 12.1(3a)XL1, RELEASE SOFTWAREUpgrading to a New Software Release
For technical information about upgrading to a new software release, see Cisco IOS Upgrade Ordering Instructions on CCO located at:
http://tools.cisco.com/Support/Fusion/FusionHome.do
Feature Set Tables
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.
Caution
Table 3 lists the voice and data software images by feature sets for the Cisco uBR905 Cable Access Router. This table uses the following conventions:
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New and Changed Information
The following sections list the new hardware and software features supported by the Cisco uBR905 Cable Access Router.
New Hardware and Software Features in Cisco IOS Release 12.1(3a) XL4
There are no new hardware and software features in the Cisco uBR905 Cable Access Router for Cisco IOS Release 12.1(3a) XL4.
New Hardware and Software Features in Cisco IOS Release 12.1(3a) XL3
There are no new hardware and software features in the Cisco uBR905 Cable Access Router for Cisco IOS Release 12.1(3a) XL3.
New Hardware Features in Release 12.1(3a)XL2
Cisco IOS Release 12.1(3a)XL2 supports the Cisco uBR905 Cable Access Router.
New Software Features in Release 12.1(3a)XL2
The following new software features are supported by the Cisco uBR905 Cable Access Router for Release 12.1(3a)XL2.
Cable Monitor Web Diagnostics Tool
The Cable Monitor is a web-based diagnostic tool to display the current status and configuration of the Cisco uBR905 router. The Cable Monitor can also be used when the cable network is down, providing an easy way for subscribers to provide necessary information to service technicians and troubleshooters.
Cisco IOS Firewall (Phase I and II)
The Cisco IOS Firewall feature set includes the following set of features:
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For detailed information, see the Cisco IOS Firewall Feature Set documentation set, as well as the section Traffic Filtering and Firewalls in the Security Configuration Guide and the Security Command Reference (available on the Documentation CD-ROM and CCO).
Cisco Secure Intrusion Detection System (IDS) Support
Cisco IOS Release 12.1(3a)XL2 supports the Cisco Secure Intrusion Detection System (IDS), formerly known as Cisco NetRanger, which is composed of three parts:
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DOCSIS 1.0+ Extensions
In addition to the other quality of service (QoS) features, DOCSIS 1.1 supports a number of features that are required for the delivery of high-quality voice traffic. To use these features before the DOCSIS 1.1 specification is finalized, Cisco has created the DOCSIS 1.0+ extensions that contain the most important of these features:
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To avoid potentially wasting bandwidth in this manner, the DOCSIS 1.0+ extensions support the dynamic creation of multiple SIDs. New Media Access Control (MAC) messages dynamically add, delete, and modify SIDs when needed. When a phone connected to the router is taken off-hook, the Cisco uBR905 router creates a SID that has the QoS parameters needed for that particular voice call. When the call terminates, the router deletes the SID, releasing its bandwidth for use elsewhere.
The DOCSIS 1.0+ features are introduced in Cisco IOS Software Release 12.0(7) XR and 12.1(1) T.
Note
DOCSIS Baseline Privacy Interface (BPI)
The DOCSIS Baseline Privacy Interface (BPI) feature is based on the DOCSIS BPI Specification (SP-BPI-I02-990319 or later revision). It provides data privacy across the Hybrid Fiber-Coaxial (HFC) network by encrypting traffic flows between the Cisco uBR905 Cable Access Router and the cable operator's CMTS.
The BPI+ (BPI Plus) feature is an enhancement to the BPI feature and is based on the DOCSIS BPI+ Specification (SP-BPI+-I04-000407 or later revision), which is still in development. In addition to the regular BPI features, BPI+ provides more secure authentication of cable modems through the use of digital certificates. Also, a cable modem can use a digital signature to verify that the software image it has downloaded has not been altered or corrupted in transit.
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DOCSIS Baseline Privacy Management Information Base
The Baseline Privacy Management Information Base (MIB), as currently defined, is available in Cisco IOS Release 12.1(3a)XL2 code. BPI allows a Simple Network Management Protocol (SNMP) manager to monitor and manage the Cisco uBR905 Cable Access Router's BPI configuration, including whether BPI is enabled, status of current authorization keys, current timeout values, real-time status counters, and additional information about authorization errors.
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Dynamic Host Configuration Protocol Proxy Support
The DHCP Proxy Support feature helps to automate the configuration of the Cisco uBR905 Cable Access Router in two situations:
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When configured for DHCP Proxy Support, during startup the Cisco uBR905 Cable Access Router sends a proxy DHCP request to the DHCP server using the Ethernet interface's MAC address. The DHCP server replies with a second IP address that the router assigns to either the Ethernet interface or to the NAT pool, depending on which option was specified.
Easy IP—DHCP Server and NAT/PAT
The Easy IP feature set includes the following features to automate the assignment and use of IP addresses:
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Enhanced Bridging
The Cisco uBR905 Cable Access Router contains four RJ-45 (10BaseT Ethernet) hub ports, which can be connected to four computers directly or one of the four ports to an Ethernet hub. The Ethernet hub connects additional computers or devices at the site. A maximum of 254 devices can be bridged in DOCSIS bridging mode; no limit exists in routing mode.
Full and DOCSIS-Compliant Bridging
DOCSIS-compliant bridging allows the Cisco uBR905 Cable Access Router to operate as a DOCSIS 1.0 cable modem, so that it can interoperate with any DOCSIS-qualified CMTS. This is the default mode of operation for the Cisco uBR905 Cable Access Router.
HSRP Support for ICMP Redirects (CSCdp37610)
The HSRP Support for ICMP Redirects feature enables Internet Control Message Protocol (ICMP) redirection on interfaces configured with the Hot Standby Router Protocol.
When running HSRP, it is important to prevent hosts from discovering the interface (or real) MAC addresses of routers in the HSRP group. If a host is redirected by ICMP to the real MAC address of a router, and that router later fails, then packets from the host will be lost. Previously, ICMP redirect messages were automatically disabled on interfaces configured with HSRP.
This feature now enables ICMP redirects on interfaces configured with HSRP. This functionality works by filtering outgoing ICMP redirect messages through HSRP, where the next-hop IP address may be changed to an HSRP virtual IP address.
IP Address Negotiation
The Cisco uBR905 Cable Access Router supports the ip address dhcp command on the cable interface. Older Cisco IOS releases used the ip address negotiated command for this purpose, but this command is now reserved for serial interfaces.
IPSec Encryption (56-bit and 3DES)
IPSec Network Security (IPSec) is an IP security feature that provides robust authentications and encryption of IP packets. IPSec is a framework of open standards developed by the Internet Engineering Task Force (IETF). IPSec provides security for transmission of sensitive information over unprotected networks such as the Internet. IPSec acts at the network layer, protecting and authenticating IP packets between participating IPSec devices ("peers") such as the Cisco uBR905 Cable Access Router.
IPSec provides the following network security services:
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Layer 2 Tunneling Protocol
Layer 2 Tunneling Protocol (L2TP) is an emerging Internet Engineering Task Force (IETF) standard that combines Cisco's Layer 2 Forwarding (L2F) and Microsoft's Point-to-Point Tunneling Protocol (PPTP). L2TP is an extension of the Point-to-Point Protocol (PPP), which is an important component for Access Virtual Private Networks (VPNs).
Traditional dial-up networking services only supported registered IP addresses, which limited the types of applications that could be implemented over VPNs. L2TP supports multiple protocols and unregistered and privately administered IP addresses over the Internet. This allows the existing access infrastructure, such as the Internet, modems, access servers, and ISDN terminal adapters (TAs), to be used.
L2TP can be initiated wherever PPTP or L2F is currently deployed and can be operated as a client initiated tunnel, such as PPTP, or a network access server (NAS) initiated tunnel, such as L2F.
Refer to the section Limitations and Restrictions on page 14 for information regarding the functionality of the Cisco uBR905 Cable Access Router in L2TP applications.
Management Information Base (MIB) Features
Cisco IOS Release 12.1(3a)XL2 supports the following MIB features:
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RFC 2233 Support
In Cisco IOS Release 12.1(3a)XL2, the IF-MIB MIB supports RFC 2233, which obsoletes the previous RFC 1573. This change adds the "ifCounterDiscontinuityTime" attribute and changes the "ifTableLastChange attribute."
In addition, this feature adds support for RFC 2233-compliant link up and link down traps. By default, link up and link down traps are implemented as given in the CISCO-IF-CAPABILITY.my MIB. To generate link up and link down traps as defined by RFC 2233, use the snmp-server trap link ietf global configuration command.
Routing (RIP V2)
When configured for routing mode, the Cisco uBR905 Cable Access Router supports the Routing Information Protocol Version 2 (RIPv2). In routing mode the Cisco uBR905 Cable Access Router automatically configures itself to use the headend's IP address as its IP default gateway. This allows the Cisco uBR905 Cable Access Router to send packets not intended for the private LAN to the headend for delivery to the Internet and other networks.
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Secure Shell Version 1 Client Support
The Secure Shell (SSH) protocol provides for authentication and encryption at the application layer, providing a secure connection even when BPI or IPSec authentication and encryption are not used at the network layer.
By default, the SSH feature uses 56-bit DES encryption. Higher security 168-bit 3DES encryption is available when using Cisco IOS images that support 3DES IPSec encryption. (The SSH client must also support the same level of encryption.)
In Cisco IOS Release 12.1(3a)XL2, SSH support includes the following features:
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SNMP Enhancements
Cisco IOS Release 12.1(3a)XL2 supports RFC 2669 and RFC 2670 for the DOCS-CABLE-DEVICE-MIB and DOCS-IF-MIB MIBs, respectively.
VPN Enhancement—Dynamic Crypto Map
Dynamic crypto map is one of the Cisco PIX IPSec network security commands. IPSec provides security for transmission of sensitive information over unprotected networks such as the Internet.
The dynamic crypto map command is used to create policy templates that are used when processing negotiation requests for new security associations from a remote IPSec peer, even if you do not know all of the crypto map parameters required to communicate with the remote peer (such as the peer's IP address). The dynamic crypto map allows you to accept requests for new security associations from previously unknown peers. These requests, however, are not processed until the Internet Security Association and Key Management Protocol (ISAKMP) Internet Key Exchange (IKE) authentication has completed successfully.
When the firewall receives a negotiation request via IKE from another IPSec peer, the request is examined to see if it matches a crypto map entry. If the negotiation does not match any explicit crypto map entry, it will be rejected unless the crypto map set includes a reference to a dynamic crypto map.
If the firewall accepts the peer's request, at the point that it installs the new IPSec security associations, it also installs a temporary crypto map entry. This entry is filled in with the results of the negotiation. At this point, the firewall performs normal processing, using this temporary crypto map entry as a normal entry, even requesting new security associations if the current ones are expiring (based on the policy specified in the temporary crypto map entry). After all of the corresponding security associations expire, the temporary crypto map entry is removed.
Dynamic crypto map sets are not used for initiating IPSec security associations. However, they are used for determining whether traffic should be protected.
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Limitations and Restrictions
This section describes warnings and cautions about using Cisco IOS Release 12.1(3a)XL2 software.
Bridging Support
The Cisco uBR905 Cable Access Router interoperates with DOCSIS cable networks. Cisco IOS Release 12.1(3a)XL2 does not support bridging traffic across a non-DOCSIS cable network.
DOCSIS CLI Commands are Removed
To comply with DOCSIS requirements that restrict access to commands that change DOCSIS parameters, Cisco IOS Release 12.1(3a)XL2 has removed a number of commands from the CLI. The following commands are now reserved exclusively for DOCSIS use:
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GRE IP Tunnels Are Not Supported
Generic routing encapsulation (GRE) IP tunnels cannot be built between two Cisco uBR905 Cable Access Routers because GRE IP tunnels are not supported in any Cisco IOS image for the Cisco uBR905 Cable Access Routers. IPSec tunnels, however, are supported when using Cisco IOS images that support IPSec encryption.
IP Address Negotiation
The DOCSIS specifications require that a cable modem obtain its IP address at power-on or reset from a DHCP server that is available through the cable interface. For this reason, the Cisco uBR905 Cable Access Router defaults to a configuration that uses the ip address dhcp command for the cable interface. It is not possible to override this setting by specifying a specific static IP address; to assign a static IP address to the Cisco uBR905 router, configure the DHCP server so that it assigns the desired IP address on the basis of the unit's MAC address.
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Upgrading Software Images Using BPI
To enable BPI encryption, the Cisco uBR905 Cable Access Router must use a Cisco IOS image that supports BPI encryption. If the router's current software image does not support BPI encryption (or if the current software image is corrupted), you must disable BPI encryption in the DOCSIS configuration file and reset the router before you will be able to download a new software image.
Using Access Lists 100 and 101
Access lists 100 and 101 are reserved for DOCSIS use and should never be configured manually on the Cisco uBR905 Cable Access Router. Use any access lists 102 through 199 instead.
Using Multiple PCs with the Cisco uBR905 Cable Access Router
The "MAX CPE" parameter in a Cisco uBR905 Cable Access Router's DOCSIS configuration file determines how many PCs (or other CPE devices) are supported by the Cisco uBR905 Cable Access Router. The default value for the "MAX CPE" parameter is 1, which means only one PC can be connected to the Cisco uBR905 Cable Access Router.
The DOCSIS 1.0 specification states that a CMTS cannot age-out MAC addresses for CPE devices, so the first PC that is connected to the Cisco uBR905 Cable Access Router is normally the only one that the CMTS recognizes as valid. If a subscriber replaces an existing PC or changes its network interface card (NIC) to one that has a different MAC address, the CMTS will refuse to let the PC come online because this would exceed the maximum number of CPE devices specified by the "MAX CPE" parameter. A similar thing would happen if a user decides to move a PC from one Cisco uBR905 router to another.
To allow a subscriber to replace an existing PC or NIC, the following workarounds are possible:
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Using the Reset Switch
The reset switch on the back panel of the Cisco uBR905 Cable Access Router is recessed to prevent accidental resets of the router. To depress the switch, use a blunt object, such as a pen or pencil point; do not use a sharp object, such as a knife or awl, because this could damage the switch and the router's circuitry.
Important Notes
This section contains important information about using Cisco IOS Release 12.1(3a)XL2 software.
CPE Device Filtering
In Cisco IOS Release 12.1(3a)XL2 and above, the "docsDevCpeIpMax" attribute defaults to -1 instead of the default of 1, which was used in previous releases. This attribute controls the maximum number of CPE devices that can pass traffic through the router from its Ethernet interface as follows:
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CPE IP address filtering is done as part of the following process:
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See the DOCS-CABLE-DEVICE-MIB.my MIB for more information on the attributes and tables listed above.
Disabling the Finger Server
By default, the Cisco uBR900 series Cable Access Router enables its onboard TCP/IP "finger" server to allow remote users to query the number and identities of any users who are logged in to the router. Unless your network operations center (NOC) requires this service, it should be disabled to prevent denial of service attacks that access the finger server's well-known port (TCP port 79). To disable the finger server, include the no service finger command in the Cisco IOS configuration file that the router downloads at initial power-on.
Supported MIBs
The Cisco uBR905 Cable Access Router supports the following categories of MIBs:
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Cable Device MIBs
The Cisco uBR905 Cable Access Router supports the Cable Device MIB, which is defined by RFC 2669 and describes DOCSIS-compliant cable modems and CMTS. The Cable Device MIB records statistics related to the configuration and status of the cable modem. Statistics include an events log and device status. The following list details the components of the Cable Device MIB:
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The Cable Device MIB is very similar to the RFI MIB in that both allow access to statistics; they are different in that the Cable Device MIB reports statistics on the cable modem, and the RFI MIB reports statistics on the radio frequency transmissions over the cable television line.
Cisco Standard MIBs
The Cisco uBR905 Cable Access Router supports the Cisco Standard MIBs, which consist of the following components:
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Radio Frequency Interface MIBs
The Cisco uBR905 Cable Access Router supports the Radio Frequency Interface (RFI) MIB. The RFI MIB module is defined in RFC 2670 and describes DOCSIS-compliant radio frequency interfaces in cable modems and CMTS. On the cable modem, RFI MIB entries provide:
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The RFI MIB includes tables describing both the CMTS and the cable modem side of the cable interface. All cable modem tables are implemented.
With IPSec, data can be transmitted across a public network without fear of observation, modification, or spoofing. This enables applications such as VPNs, extranets, and remote user access.
IPSec services are similar to those provided by Cisco Encryption Technology, a proprietary Cisco security solution. However, IPSec provides a more robust security solution, and is standards based.
Cable-Specific MIBs
Table 4 shows the cable-specific MIBs that are supported on the Cisco uBR905 Cable Access Router. This table also provides a brief description of each MIB's contents and the Cisco IOS software release in which the MIB was initially functional—earlier releases might have had unsupported prototype versions of the MIB; later releases might have added new attributes and functionality.
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Deprecated MIBs
A number of Cisco-provided MIBs have been replaced with more scalable, standardized MIBs; these MIBs have filenames that start with "OLD" and first appeared in Cisco IOS Release 10.2. The functionality of these MIBs has already been incorporated into replacement MIBs, but the old MIBs are still present to support existing Cisco IOS products or network management system (NMS) applications. However, because the deprecated MIBs will be removed from support in the future, you should update your network management applications and scripts to refer to the table names and attributes that are found in the replacement MIBs.
Table 5 shows the deprecated MIBs and their replacements. In most cases, SNMPv1 and SNMPv2 replacements are available, but some MIBs are available only in one version. A few of the deprecated MIBs do not have replacement MIBs; support for these MIBs will be discontinued in a future release of Cisco IOS software.
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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 contains open and resolved caveats for Cisco IOS Release 12.1(3a)XL2. All caveats in Release 12.1 T are also in Release 12.1(3a)XL2.
For information on caveats in Cisco IOS Release 12.1 T, see Caveats for Cisco IOS Release 12.1 T, which lists severity 1 and 2 caveats, and is located on CCO and the Documentation CD-ROM.
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Open Caveats—Cisco IOS Release12.1(3a)XL4
There are no open caveats specific to Cisco IOS Release 12.2(2)XA5 that require documentation in the release notes.
Resolved Caveats—Cisco IOS Release12.1(3a)XL4
All the caveats listed in this section are resolved in Cisco IOS Release 12.1(3a)XL4. This section describes only severity 1 and 2 caveats and select severity 3 caveats.
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An error can occur with management protocol processing. Please use the following URL for further information:
http://www.cisco.com/cgi-bin/bugtool/onebug.pl?bugid=CSCdw65903
Open Caveats—Release 12.1(3a)XL2
All the caveats listed in this section are open in Release 12.1(3a)XL2:
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The Cisco uBR905 router, when running the NAT and firewall features, crashes if establishing roughly 150 Telnet sessions (using the solaris_telnet client). The workaround is to avoid creating that many Telnet sessions.
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Packets can be unexpectedly dropped on the upstream channel when the Cisco uBR905 is configured to use DOCSIS concatenation and the upstream is using 16 QAM symbol rate. The workaround is to configure the CMTS for a preamble with Unique Word 16 for both the short and long data burst profile. On the Cisco uBR7200 series universal broadband routers, this can be done with the cable modulation-profile global configuration command, specifying uw16 for both the long and short modulation profiles.
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The show interface command can show an impossible number of CRC errors on the cable interface when transmitting VoIP traffic. When this error occurs, the number of CRC errors typically exceeds a billion errors and is greater than the total number of packets transmitted on the interface. The workaround is to use the show interface cable 0 counters command to display the correct number of errors.
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The Cisco uBR905 Cable Access Router might reload when using an access list numbered 100 or 101 while running Cisco IOS Release 12.1 XL images that support any form of IPSec encryption. Other access lists, however, can be used without problem.
Workaround: Do not configure access list numbers 100 and 101 for any purpose. Use access lists 102 through 199 instead.
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