Cisco cBR Series User manual

Cisco cBR Series Converged Broadband Routers Application—Voice
and Video Configuration Guide
First Published: March 26, 2015
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©2015 Cisco Systems, Inc. All rights reserved.

CONTENTS
CHAPTER 1 Unique Device Identifier Retrieval 1
Hardware Compatibility Matrix for Cisco cBR Series Routers 1
Unique Device Identifier Overview 2
Benefits of the Unique Device Identifier Retrieval Feature 2
Retrieving the Unique Device Identifier 3
Troubleshooting Tips 5
Additional References 6
Feature Information for Unique Device Identifier Retrieval 7
CHAPTER 2 Advanced-Mode DOCSIS Set-Top Gateway 1.2 for the Cisco CMTS Routers 9
Hardware Compatibility Matrix for Cisco cBR Series Routers 10
Prerequisites for Advanced-Mode DSG Issue 1.2 10
Restrictions for Advanced-Mode DSG Issue 1.2 10
DSG Configuration File Transfer Operations 10
Multicast Configuration Restrictions 10
NAT for DSG Unicast-only Mapping 11
PIM and SSM for Multicast 11
Subinterfaces 11
Information About Advanced-Mode DSG Issue 1.2 11
DSG 1.2 Clients and Agents 12
FQDN Support 12
DSG Name Process and DNS Query 12
A-DSG Forwarding on the Primary Channel 13
DOCSIS 3.0 DSG MDF Support 13
Source Specific Multicast Mapping 13
How to Configure Advanced-Mode DSG Issue 1.2 14
Configuring the Default Multicast Quality of Service 14
Configuring Global Tunnel Group Settings for Advanced-Mode DSG 1.2 15
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Global A-DSG 1.2 Tunnel Settings 15
Adding DSG Tunnel Group to a Subinterface 17
Configuring the DSG Client Settings for Advanced-Mode DSG 1.2 18
Configuring Downstream DSG 1.2 Settings for Advanced-Mode DSG 1.2 19
Configuring IP Multicast Operations 20
Enabling DNS Query and DSG Name Process 22
Configuring NAT to Support Unicast Messaging 23
Configuring WAN Interfaces for Multicast Operations 25
Configuring a Standard IP Access List for Packet Filtering 25
Configuring a Standard IP Access List for Multicast Group Filtering 27
Disabling A-DSG Forwarding on the Primary Channel 28
How to Monitor and Debug the Advanced-mode DOCSIS Set-Top Gateway Feature 29
Displaying Global Configurations for Advanced-Mode DSG 1.2 29
show cable dsg cfr 29
show cable dsg host 29
show cable dsg tunnel 29
show cable dsg tg 30
show running-config interface 30
show cable dsg static-group bundle 30
Displaying Interface-level Configurations for Advanced-Mode DSG 1.2 31
show cable dsg tunnel interfaces 31
show interfaces cable dsg downstream 31
show interfaces cable dsg downstream dcd 31
show interfaces cable dsg downstream tg 31
show interfaces cable dsg downstream tunnel 31
Debugging Advanced-Mode DSG 31
Configuration Examples for Advanced-Mode DSG 31
Example: Enabling DNS Query 35
Example: Disabling A-DSG Forwarding on the Primary Channel 35
Additional References 35
Feature Information for Advanced-Mode DSG 1.2 for the Cisco CMTS Routers 35
CHAPTER 3 Cisco Network Registrar for the Cisco CMTS Routers 37
Hardware Compatibility Matrix for Cisco cBR Series Routers 38
Servers Required on the HFC Network 38
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Cisco Network Registrar Description 39
Overview of DHCP Using CNR 40
How Cisco Converged Broadband Routers and Cable Modems Work 41
DHCP Fields and Options for Cable Modems 42
Cisco Network Registrar Sample Configuration 43
Cable Modem DHCP Response Fields 45
DOCSIS DHCP Fields 45
DHCP Relay Option (DOCSIS Option 82) 46
Overview of Scripts 46
Two-way Cable Modem Scripts 46
Telco Return Cable Modem Scripts 46
Placement of Scripts 47
Windows NT 47
Solaris 47
Activating Scripts in Cisco Network Registrar 47
Configuring the Cisco CMTS Routers to Use Scripts 47
Configuring the System Default Policy 48
Cable Modems 48
PCs 48
Creating Selection Tag Scopes 48
General 48
Telco Return for the Cisco cBR-8 Router 49
Creating Network Scopes 49
Creating Policies for Class of Service or for Upgrading Cable Modem Cisco IOS Images 50
CNR Steps to Support Subinterfaces 50
Additional References 51
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CHAPTER 1
Unique Device Identifier Retrieval
The Unique Device Identifier (UDI) Retrieval feature provides the ability to retrieve and display the UDI
information from any Cisco product that has electronically stored such identity information.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature
information and caveats, see the release notes for your platform and software release. To find information
about the features documented in this module, and to see a list of the releases in which each feature is
supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An account on http://
www.cisco.com/ is not required.
Contents
•Hardware Compatibility Matrix for Cisco cBR Series Routers, page 1
•Unique Device Identifier Overview, page 2
•Benefits of the Unique Device Identifier Retrieval Feature, page 2
•Retrieving the Unique Device Identifier, page 3
•Troubleshooting Tips, page 5
•Additional References, page 6
•Feature Information for Unique Device Identifier Retrieval , page 7
Hardware Compatibility Matrix for Cisco cBR Series Routers
The hardware components introduced in a given Cisco IOS-XE Release are supported in all subsequent
releases unless otherwise specified.
Note
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Table 1: Hardware Compatibility Matrix for the Cisco cBR Series Routers
Interface CardsProcessor EngineCisco CMTS Platform
Cisco IOS-XE Release 3.15.0S
and Later Releases
Cisco cBR-8 CCAP Line Cards:
•PID—CBR-LC-8D30-16U30
•PID—CBR-RF-PIC
•PID—CBR-RF-PROT-PIC
Cisco IOS-XE Release 3.15.0S
and Later Releases
Cisco cBR-8 Supervisor:
•PID—CBR-CCAP-SUP-160G
•PID—CBR-SUP-8X10G-PIC
Cisco cBR-8 Converged
Broadband Router
Unique Device Identifier Overview
Each identifiable product is an entity, as defined by the Entity MIB (RFC-2737) and its supporting documents.
Some entities, such as a chassis, will have sub-entities like slots. An Ethernet switch might be a member of
a super-entity like a stack. Most Cisco entities that can be ordered leave the factory with an assigned UDI.
The UDI information is printed on a label that is affixed to the physical hardware device, and it is also stored
electronically on the device in order to facilitate remote retrieval.
A UDI consists of the following elements:
•Product identifier (PID)
•Version identifier (VID)
•Serial number (SN)
The PID is the name by which the product can be ordered; it has been historically called the “Product Name”
or “Part Number.”This is the identifier that one would use to order an exact replacement part.
The VID is the version of the product. Whenever a product has been revised, the VID will be incremented.
The VID is incremented according to a rigorous process derived from Telcordia GR-209-CORE, an industry
guideline that governs product change notices.
The SN is the vendor-unique serialization of the product. Each manufactured product will carry a unique serial
number assigned at the factory, which cannot be changed in the field. This is the means by which to identify
an individual, specific instance of a product.
Benefits of the Unique Device Identifier Retrieval Feature
•Identifies individual Cisco products in your networks.
•Reduces operating expenses for asset management through simple, cross-platform, consistent identification
of Cisco products.
•Identifies PIDs for replaceable products.
•Facilitates discovery of products subject to recall or revision.
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Unique Device Identifier Overview

•Automates Cisco product inventory (capital and asset management).
•Provides a mechanism to determine the entitlement level of a Cisco product for repair and replacement
service.
Product Item Descriptor for Cable Products
For information on the Product Item Descriptor (PID), see the product hardware installation guide available
on Cisco.com.
Retrieving the Unique Device Identifier
To use UDI retrieval, the Cisco product in use must be UDI-enabled. A UDI-enabled Cisco product supports
five required Entity MIB objects. The five Entity MIB v2 (RFC-2737) objects are:
•entPhysicalName
•entPhysicalDescr
•entPhysicalModelName
•entPhysicalHardwareRev
•entPhysicalSerialNum
Although the show inventory command may be available, using that command on devices that are not
UDI-enabled will likely produce no output.
Enter the show inventory command to retrieve and display information about all of the Cisco products installed
in the networking device that are assigned a PID, VID, and SN. If a Cisco entity is not assigned a PID, that
entity is not retrieved or displayed.
Router# show inventory
NAME: "Chassis", DESCR: "Cisco cBR-8 CCAP Chassis"
PID: CBR-8-CCAP-CHASS , VID: V01, SN: FXS1739Q0PR
NAME: "clc 3", DESCR: "Cisco cBR CCAP Line Card"
PID: CBR-CCAP-LC-40G , VID: V01, SN: TEST1234567
NAME: "Cable PHY Module", DESCR: "CLC Downstream PHY Module 3/0"
PID: CBR-D30-DS-MOD , VID: V01, SN: CAT1725E1BZ
NAME: "Cable PHY Module", DESCR: "CLC Downstream PHY Module 3/1"
PID: CBR-D30-DS-MOD , VID: V01, SN: CAT1725E1AT
NAME: "Cable PHY Module", DESCR: "CLC Upstream PHY Module 3/2"
PID: CBR-D30-US-MOD , VID: V01, SN: CAT1717E0FF
NAME: "sup 1", DESCR: "Cisco cBR CCAP Supervisor Card"
PID: CBR-CCAP-SUP-60G , VID: V01, SN: CAT1824E0MT
NAME: "harddisk 5/1", DESCR: "Hard Disk"
PID: UGB88RTB100HE3-BCU-DID, VID: , SN: 11000066829
NAME: "sup-pic 5/1", DESCR: "Cisco cBR CCAP Supervisor Card PIC"
PID: CBR-SUP-8X10G-PIC , VID: V01, SN: CAT1720E0F4
NAME: "SFP+ module 5/1/0", DESCR: "iNSI xcvr"
PID: SFP+ 10GBASE-SR , VID: A , SN: FNS172720X6
NAME: "SFP+ module 5/1/1", DESCR: "iNSI xcvr"
PID: SFP+ 10GBASE-LR , VID: A , SN: UGT085P
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Retrieving the Unique Device Identifier

NAME: "SFP+ module 5/1/2", DESCR: "iNSI xcvr"
PID: SFP+ 10GBASE-LR , VID: A , SN: UGT087Z
NAME: "SFP+ module 5/1/3", DESCR: "iNSI xcvr"
PID: SFP+ 10GBASE-SR , VID: G4.1, SN: AVD1729A38T
NAME: "SFP+ module 5/1/7", DESCR: "iNSI xcvr"
PID: 10GE ZR , VID: A , SN: FNS11300AUH
NAME: "Power Supply Module 0", DESCR: "Cisco cBR CCAP AC Power Supply"
PID: PWR-3KW-AC-V2 , VID: V02, SN: DTM17370345
NAME: "Power Supply Module 2", DESCR: "Cisco cBR CCAP AC Power Supply"
PID: PWR-3KW-AC-V2 , VID: V02, SN: DTM173702KF
For diagnostic purposes, the show inventory command can be used with the raw keyword to display every
RFC 2737 entity including those without a PID, UDI, or other physical identification.
The raw keyword option is primarily intended for troubleshooting problems with the show inventory
command itself.
Note
Router# show inventory raw
NAME: "Chassis", DESCR: "Cisco cBR-8 CCAP Chassis"
PID: CBR-8-CCAP-CHASS , VID: V01, SN: FXS1739Q0PR
NAME: "slot 0/0", DESCR: "Chassis Slot"
PID: , VID: , SN:
NAME: "slot 0/1", DESCR: "Chassis Slot"
PID: , VID: , SN:
NAME: "slot 1/0", DESCR: "Chassis Slot"
PID: , VID: , SN:
NAME: "slot 1/1", DESCR: "Chassis Slot"
PID: , VID: , SN:
NAME: "slot 2/0", DESCR: "Chassis Slot"
PID: , VID: , SN:
NAME: "slot 2/1", DESCR: "Chassis Slot"
PID: , VID: , SN:
NAME: "slot 3/0", DESCR: "Chassis Slot"
PID: , VID: , SN:
NAME: "clc 3", DESCR: "Cisco cBR CCAP Line Card"
PID: CBR-CCAP-LC-40G , VID: V01, SN: TEST1234567
NAME: "12_CUR: Sens 3/0", DESCR: "12_CUR: Sens"
PID: , VID: , SN:
NAME: "12_CUR: Vin 3/1", DESCR: "12_CUR: Vin"
PID: , VID: , SN:
NAME: "12_CUR: ADin 3/2", DESCR: "12_CUR: ADin"
PID: , VID: , SN:
NAME: "G0_CUR: Sens 3/3", DESCR: "G0_CUR: Sens"
PID: , VID: , SN:
NAME: "G0_CUR: Vin 3/4", DESCR: "G0_CUR: Vin"
PID: , VID: , SN:
NAME: "G0_CUR: ADin 3/5", DESCR: "G0_CUR: ADin"
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Retrieving the Unique Device Identifier

PID: , VID: , SN:
NAME: "G1_CUR: Sens 3/6", DESCR: "G1_CUR: Sens"
PID: , VID: , SN:
NAME: "G1_CUR: Vin 3/7", DESCR: "G1_CUR: Vin"
PID: , VID: , SN:
NAME: "G1_CUR: ADin 3/8", DESCR: "G1_CUR: ADin"
PID: , VID: , SN:
NAME: "LB_CUR: Sens 3/9", DESCR: "LB_CUR: Sens"
PID: , VID: , SN:
NAME: "LB_CUR: Vin 3/10", DESCR: "LB_CUR: Vin"
PID: , VID: , SN:
NAME: "LB_CUR: ADin 3/11", DESCR: "LB_CUR: ADin"
PID: , VID: , SN:
NAME: "Temp: CAPRICA 3/12", DESCR: "Temp: CAPRICA"
PID: , VID: , SN:
NAME: "Temp: BASESTAR 3/13", DESCR: "Temp: BASESTAR"
PID: , VID: , SN:
NAME: "Temp: RAIDER 3/14", DESCR: "Temp: RAIDER"
PID: , VID: , SN:
NAME: "Temp: CPU 3/15", DESCR: "Temp: CPU"
PID: , VID: , SN:
NAME: "Temp: INLET 3/16", DESCR: "Temp: INLET"
PID: , VID: , SN:
NAME: "Temp: OUTLET 3/17", DESCR: "Temp: OUTLET"
PID: , VID: , SN:
NAME: "Temp: DIGITAL 3/18", DESCR: "Temp: DIGITAL"
PID: , VID: , SN:
NAME: "Temp: UPX 3/19", DESCR: "Temp: UPX"
PID: , VID: , SN:
Troubleshooting Tips
If any of the Cisco products do not have an assigned PID, the output may display incorrect PIDs and the VID
and SN elements may be missing, as in the following example.
NAME: "POS3/0/0", DESCR: "Skystone 4302 Sonet Framer"
PID: FastEthernet, VID: , SN:
NAME: "Serial1/0", DESCR: "M4T"
PID: M4T , VID: , SN:
In the sample output, the PID is exactly the same as the product description. The UDI is designed for use with
new Cisco products that have a PID assigned. UDI information on older Cisco products is not always reliable.
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Unique Device Identifier Retrieval
Troubleshooting Tips

Additional References
Related Documents
Document TitleRelated Topic
Cisco IOS Configuration Fundamentals Configuration
Guide
Information about managing configuration files
Cisco IOS Interface Command Reference
Commands for showing interface statistics
Standards and RFCs
TitleStandard/RFC
Entity MIB (Version 2)
RFC 2737
MIBs
MIBs LinkMIB
To locate and download MIBs for selected platforms,
Cisco IOS releases, and feature sets, use Cisco MIB
Locator found at the following URL:
http://www.cisco.com/go/mibs
CISCO-ENTITY-ASSET-MIB
Technical Assistance
LinkDescription
http://www.cisco.com/cisco/web/support/index.html
The Cisco Support website provides extensive online
resources, including documentation and tools for
troubleshooting and resolving technical issues with
Cisco products and technologies.
To receive security and technical information about
your products, you can subscribe to various services,
such as the Product Alert Tool (accessed from Field
Notices), the Cisco Technical Services Newsletter,
and Really Simple Syndication (RSS) Feeds.
Access to most tools on the Cisco Support website
requires a Cisco.com user ID and password.
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Unique Device Identifier Retrieval
Additional References

Feature Information for Unique Device Identifier Retrieval
Use Cisco Feature Navigator to find information about platform support and software image support.
Cisco Feature Navigator enables you to determine which software images support a specific software release,
feature set, or platform. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An
account on http://www.cisco.com/ is not required.
The below table lists only the software release that introduced support for a given feature in a given
software release train. Unless noted otherwise, subsequent releases of that software release train also
support that feature.
Note
Table 2: Feature Information for Unique Device Identifier Retrieval
Feature InformationReleasesFeature Name
This feature was introduced on the
Cisco cBR Series Converged
Broadband Routers.
Cisco IOS-XE Release 3.15.0SUnique Device Identifier Retrieval
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Unique Device Identifier Retrieval
Feature Information for Unique Device Identifier Retrieval

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Unique Device Identifier Retrieval
Feature Information for Unique Device Identifier Retrieval

CHAPTER 2
Advanced-Mode DOCSIS Set-Top Gateway 1.2
for the Cisco CMTS Routers
The Advanced-Mode DOCSIS Set-Top Gateway (A-DSG) Issue 1.2 introduces support for the latest DOCSIS
Set-Top specification from CableLabs™, to include the following enhancements:
•DOCSIS Set-top Gateway (DSG) Interface Specification
•A-DSG 1.2 introduces support for the DOCS-DSG-IF MIB.
Cisco A-DSG 1.2 is certified by CableLabs™, and is a powerful tool in support of latest industry innovations.
A-DSG 1.2 offers substantial support for enhanced DOCSIS implementation in the broadband cable
environment. The set-top box (STB) dynamically learns the overall environment from the Cisco CMTS
router, to include MAC address, traffic management rules, and classifiers.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature
information and caveats, see the release notes for your platform and software release. To find information
about the features documented in this module, and to see a list of the releases in which each feature is
supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An account on http://
www.cisco.com/ is not required.
Contents
•Hardware Compatibility Matrix for Cisco cBR Series Routers, page 10
•Prerequisites for Advanced-Mode DSG Issue 1.2, page 10
•Restrictions for Advanced-Mode DSG Issue 1.2, page 10
•Information About Advanced-Mode DSG Issue 1.2, page 11
•How to Configure Advanced-Mode DSG Issue 1.2, page 14
•How to Monitor and Debug the Advanced-mode DOCSIS Set-Top Gateway Feature, page 29
•Configuration Examples for Advanced-Mode DSG, page 31
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•Additional References, page 35
•Feature Information for Advanced-Mode DSG 1.2 for the Cisco CMTS Routers, page 35
Hardware Compatibility Matrix for Cisco cBR Series Routers
The hardware components introduced in a given Cisco IOS-XE Release are supported in all subsequent
releases unless otherwise specified.
Note
Table 3: Hardware Compatibility Matrix for the Cisco cBR Series Routers
Interface CardsProcessor EngineCisco CMTS Platform
Cisco IOS-XE Release 3.15.0S
and Later Releases
Cisco cBR-8 CCAP Line Cards:
•PID—CBR-LC-8D30-16U30
•PID—CBR-RF-PIC
•PID—CBR-RF-PROT-PIC
Cisco IOS-XE Release 3.15.0S
and Later Releases
Cisco cBR-8 Supervisor:
•PID—CBR-CCAP-SUP-160G
•PID—CBR-SUP-8X10G-PIC
Cisco cBR-8 Converged
Broadband Router
Prerequisites for Advanced-Mode DSG Issue 1.2
No special equipment or software is needed to use the Advanced-Mode DSG Issue 1.2 feature.
Restrictions for Advanced-Mode DSG Issue 1.2
This section contains restrictions that are specific to A-DSG 1.2 on a Cisco CMTS router.
DSG Configuration File Transfer Operations
DSG 1.2 does not support the copying of a DSG configuration file from a TFTP server, file system, or bootflash
to the running configuration.
Multicast Configuration Restrictions
IP multicasting must be configured for correct operation of A-DSG 1.2. Specifically, IP multicast routing
must be set in global configuration. Also, IP PIM must be configured on all bundle interfaces of cable interfaces
that are to carry multicast traffic.
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Advanced-Mode DOCSIS Set-Top Gateway 1.2 for the Cisco CMTS Routers
Hardware Compatibility Matrix for Cisco cBR Series Routers

See the Configuring the Default Multicast Quality of Service, on page 14 and the Configuring IP Multicast
Operations, on page 20 for additional Multicast information and global configurations supporting DSG.
NAT for DSG Unicast-only Mapping
A-DSG 1.2 supports multicast IP addressing. However, it also supports unicast IP destination addresses. On
the Cisco cBR-8 router, DSG 1.2 support is provided with the configuration of Network Address Translation
(NAT) on the router, to include these settings:
•WAN interface(s) are configured with the ip nat outside command.
•Cable interface(s) are configured with the ip nat inside command.
•For each mapping, additional configuration includes the source static multicast IP address and the unicast
IP address.
The unicast IP address is the unicast destination IP address of the DSG packets arriving at the Cisco CMTS
router. The multicast IP address is the new destination IP address that is configured to map to one or a set of
DSG tunnels.
PIM and SSM for Multicast
When using Source Specific Multicast (SSM) operation in conjunction with A-DSG 1.2, the following
system-wide configuration command must be specified:
•ip pim ssm
Refer to the Configuring IP Multicast Operations, on page 20.
Subinterfaces
A-DSG 1.2 supports subinterfaces on the Cisco CMTS router.
Information About Advanced-Mode DSG Issue 1.2
A-DSG 1.2 offers these new or enhanced capabilities:
•A-DSG client and agent modes
•Advanced-mode MIBs supporting DSG 1.2, including the DOCS-DSG-IF-MIB
•Advanced-mode tunnels with increased security
•Cable interface bundling through virtual interface bundling
•Downstream Channel Descriptor
•IP multicast support
•Quality of Service (QoS)
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Advanced-Mode DOCSIS Set-Top Gateway 1.2 for the Cisco CMTS Routers
NAT for DSG Unicast-only Mapping

DSG 1.2 Clients and Agents
A-DSG 1.2 supports the DSG client and agent functions outlined by the CableLabs™DOCSIS Set-top Gateway
(DSG) Interface Specification , CM-SP-DSG-I05-050812.
FQDN Support
You can specify either a fully-qualified domain name (FQDN) or IP address for A-DSG classifier multicast
group and source addresses using the cable dsg cfr command in global configuration mode. We recommend
that you use an FQDN to avoid modification of multicast group and source addresses when network changes
are implemented.
This feature allows you to use a hostname (FQDN) in place of the source IP address using the cable dsg cfr
command. For example, you have two A-DSG tunnel servers, in two locations, sending multicast traffic to
the same multicast address. In this scenario, you can specify a hostname for the source IP address and let the
DNS server determine which source is sending the multicast traffic.
If you configure an A-DSG classifier with a hostname, the Cisco CMTS router immediately verifies if the
hostname can be resolved against an IP address using the local host cache. If not, the router does not enable
the classifier until the hostname is resolved. If the hostname cannot be resolved locally, the router performs
a DNS query to verify the DSG classifiers.
The FQDN format does not support static Internet Group Management Protocol (IGMP) join requests initiated
on the Cisco CMTS router. The IGMP static group IP address created automatically under a bundle interface
at the time of A-DSG configuration is not displayed in the show running-config interface command output.
To display the A-DSG static groups configured under a bundle interface, use the show cable dsg static-group
bundle command in privileged EXEC mode.
DSG Name Process and DNS Query
Every DNS record contains a time to live (TTL) value set by the server administrator, and this may vary from
seconds to weeks. The DSG name process supersedes the TTL value criterion to update A-DSG classifiers
on the Cisco CMTS router.
The DSG name process enables the Cisco CMTS router to query the DNS server for faster classifier updates.
To enable the Cisco CMTS router to perform a DNS query for an A-DSG classifier verification, you must
configure one or more DNS servers using the ip name-server command in global configuration mode. You
can also specify the DNS query interval using the cable dsg name-update-interval command in global
configuration mode.
During a Cisco IOS software reload or a route processor switchover, the router may fail to query the DNS
server if the interfaces are down, and the router may not wait for the interval specified using the cable dsg
name-update-interval command to perform a DNS query. In this case, for an unresolved hostname, the router
automatically performs a DNS query based on a system-defined (15 seconds) interval to facilitate faster DSG
classifier updates. You cannot change the system-defined interval.
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DSG 1.2 Clients and Agents

A-DSG Forwarding on the Primary Channel
You can disable A-DSG forwarding per primary capable interface using the cable downstream dsg disable
command in interface configuration mode. Primary capable interfaces include modular, integrated cable
interfaces, and Cisco cBR-8 CCAP cable interfaces.
For example, assume the cable interface 7/1/1 has A-DSG enabled and has four modular channels attached
to it. However, you want A-DSG forwarding enabled only on two of these four modular channels. You can
exclude the channels of your choice using the cable downstream dsg disable command. For details on how
to disable modular channels, see the Disabling A-DSG Forwarding on the Primary Channel, on page 28.
If A-DSG downstream forwarding is disabled on a primary capable interface, the router does not create
multicast service flows on the primary capable interface and stops sending Downstream Channel Descriptor
(DCD) messages.
Note
DOCSIS 3.0 DSG MDF Support
Support for DOCSIS 3.0 DSG Multicast DSID Forwarding (MDF) is introduced using DSG DA-to-DSID
Association Entry type, length, value (TLV 13) in the MAC domain descriptor (MDD) message to communicate
the association between a downstream service identifier (DSID) and a group MAC address used for DSG
tunnel traffic. This is automatically supported on the Cisco CMTS router.
DOCSIS 2.0 hybrid CMs and DOCSIS 3.0 CMs use Dynamic Bonding Change (DBC) to get DSID information
from the Cisco CMTS router, whereas DOCSIS 2.0 DSG hybrid embedded CMs and DOCSIS 3.0 DSG
embedded CMs get DSID information from the Cisco CMTS router through MDD messages.
To disable MDF capability on all DSG embedded cable modems, including DOCSIS 3.0 DSG and DOCSIS
2.0 DSG hybrid modems, use the cable multicast mdf-disable command with the dsg keyword in global
configuration mode.
Source Specific Multicast Mapping
Source Specific Multicast (SSM) is a datagram delivery model that best supports one-to-many applications,
also known as broadcast applications. SSM is a core networking technology for the Cisco implementation of
IP multicast solutions targeted for audio and video broadcast application environments.
The following two Cisco IOS components together support the implementation of SSM:
•Protocol Independent Multicast source-specific mode (PIM-SSM)
•Internet Group Management Protocol Version 3 (IGMPv3)
SSM mapping can be configured on Cisco CMTS routers.
For details on how to configure SSM mapping on a Cisco CMTS router, see the Source Specific Multicast
(SSM) Mapping feature guide.
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Advanced-Mode DOCSIS Set-Top Gateway 1.2 for the Cisco CMTS Routers
A-DSG Forwarding on the Primary Channel

How to Configure Advanced-Mode DSG Issue 1.2
Advanced-mode DSG Issue 1.2 entails support for DSG tunnel configuration, to include global, WAN-side,
and interface-level settings in support of Multicast.
Configuring the Default Multicast Quality of Service
According to DOCSIS 3.0, you must configure the default multicast quality of service (MQoS) when using
the MQoS. This also applies to the DSG, which uses the MQoS by associating a service class name with the
tunnel.
If the default MQoS is not configured, the DSG tunnel service class configuration is rejected. Similarly, if no
DSG tunnel uses the MQoS, you are prompted to remove the default MQoS.
The CMTS selects the primary downstream channel to forward the multicast traffic when the default MQoS
is configured and there is no matching MQoS group configuration. Otherwise, the wideband interface is used
to forward the multicast traffic.
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Router> enable
•Enter your password if prompted.
Enters global configuration mode.configure terminal
Example:
Router# configure terminal
Step 2
Example:
Router(config)#
Configures a service class name for the
QoS profile.
cable multicast group-qos default scn
service-class-name aggregate
Example:
Router(config)# cable multicast group-qos
default scn name1 aggregate
Step 3
Returns to privileged EXEC mode.end
Example:
Router(config)# end
Step 4
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Advanced-Mode DOCSIS Set-Top Gateway 1.2 for the Cisco CMTS Routers
How to Configure Advanced-Mode DSG Issue 1.2