- Read Me First
- Preparing for Broadband Access Aggregation
- Providing Protocol Support for Broadband Access Aggregation of PPPoE Sessions
- PPP for IPv6
- DHCP for IPv6 Broadband
- Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
- Providing Connectivity Using ATM Routed Bridge Encapsulation over PVCs
- PPPoE Circuit-Id Tag Processing
- Configuring PPP over Ethernet Session Limit Support
- PPPoE Session Limit Local Override
- PPPoE QinQ Support
- PPP-Max-Payload and IWF PPPoE Tag Support
- PPPoE Session Limiting on Inner QinQ VLAN
- PPPoE Agent Remote-ID and DSL Line Characteristics Enhancement
- Enabling PPPoE Relay Discovery and Service Selection Functionality
- Configuring Cisco Subscriber Service Switch Policies
- AAA Improvements for Broadband IPv6
- Per Session Queueing and Shaping for PPPoEoVLAN Using RADIUS
- 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- PPP over Ethernet Client
- PPPoE Smart Server Selection
- Monitoring PPPoE Sessions with SNMP
- PPPoE on ATM
- PPPoE on Ethernet
- PPPoE over VLAN Enhancements Configuration Limit Removal and ATM Support
- ADSL Support in IPv6
- Broadband IPv6 Counter Support at LNS
- PPP IP Unique Address and Prefix Detection
- PPP IPv4 Address Conservation in Dual Stack Environments
- TR-069 Agent
- Broadband High Availability Stateful Switchover
- Broadband High Availability In-Service Software Upgrade
- Controlling Subscriber Bandwidth
- PPPoE Service Selection
- Disabling AC-name and AC-cookie Tags from PPPoE PADS
- Broadband Smart Licensing
- Finding Feature Information
- Prerequisites for Preparing for Broadband Access Aggregation
- Restrictions for Preparing for Broadband Access Aggregation
- Information About Preparing for Broadband Access Aggregation
- How to Prepare for Broadband Access Aggregation
Preparing for Broadband Access Aggregation
Before you begin to perform the tasks required to accomplish broadband access aggregation, there are several preparatory tasks that you can perform at your option to enable you to complete the aggregation task with more efficiency. This module presents three of those preparation tasks: configuring permanent virtual circuits (PVCs), configuring a virtual template interface, and configuring enhancements for broadband scalability.
In a digital subscriber line (DSL) environment, many applications require the configuration of a large number of PVCs. Configuring PVCs before you start broadband aggregation can save you time because configuring a range of PVCs is faster than configuring PVCs individually.
A virtual template interface saves time because all PPP parameters are managed within the virtual template configuration. Any configurations made in the virtual template are automatically propagated to the individual virtual access interfaces.
Using the enhancement for broadband scalability reduces the amount of memory that is used per terminated PPP session by creating virtual access subinterfaces. Determining if virtual access subinterfaces are available on your system and preconfiguring these enhancements can speed your aggregation process and improve system performance.
- Finding Feature Information
- Prerequisites for Preparing for Broadband Access Aggregation
- Restrictions for Preparing for Broadband Access Aggregation
- Information About Preparing for Broadband Access Aggregation
- How to Prepare for Broadband Access Aggregation
- Configuration Examples for Preparing for Broadband Access Aggregation
- Additional References
- Feature Information for Preparing for Broadband Access Aggregation
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Preparing for Broadband Access Aggregation
Before configuring broadband access aggregation, you will need to know the information that is presented in the "Understanding Broadband Access Aggregation" module.
Additional information can be found in these documents:
Configuring a PVC range--For detailed information about configuring individual ATM PVCs, see "Configuring PVCs" in the Cisco IOS Wide-Area Networking Configuration Guide.
Creating a virtual template--For detailed information see the "Configuring Virtual Template Interfaces" chapter in the Cisco IOS Dial Technologies Configuration Guide.
Restrictions for Preparing for Broadband Access Aggregation
Due to high scaling requirements, only virtual access subinterfaces are supported. Disabling virtual access subinterfaces is not supported.
Precloning virtual access interfaces is not supported.
When an interface has large number of subinterfaces disabled, the interface's Remote Access (RA) messages that have a lifetime value of zero are not sent to all its subinterfaces.
Information About Preparing for Broadband Access Aggregation
- Virtual Access Interfaces
- Configuration Enhancements for Broadband Scalability
- Benefits of Broadband Scalability Features
Virtual Access Interfaces
A virtual template interface is used to provide the configuration for dynamically created virtual access interfaces. It is created by users and can be saved in NVRAM.
Once the virtual template interface is created, it can be configured in the same way as a serial interface.
Virtual template interfaces can be created and applied by various applications such as virtual profiles, virtual private dialup networks (VPDNs), and protocol translation.
All PPP parameters are managed within the virtual template configuration. Configuration changes made to the virtual template are automatically propagated to the individual virtual access interfaces. Multiple virtual access interfaces can originate from a single virtual template.
Cisco IOS XE software supports up to 4096 virtual template configurations. If greater numbers of tailored configurations are required, an authentication, authorization, and accounting (AAA) server can be used.
If the parameters of the virtual template are not explicitly defined before the interface is configured, the PPP interface is brought up using default values from the virtual template. Some parameters (such as an IP address) take effect only if specified before the PPP interface comes up. Therefore, it is recommended that you explicitly create and configure the virtual template before configuring the interface to ensure that such parameters take effect. Alternatively, if parameters are specified after the interface has been configured, use the shutdown command followed by the no shutdown command on the subinterface to restart the interface; this restart will cause the newly configured parameters (such as an IP address) to take effect.
Configuration Enhancements for Broadband Scalability
The Configuration Enhancements for Broadband Scalability feature reduces the amount of memory that is used per terminated PPP session by creating virtual-access subinterfaces. Depending on the configuration of the source virtual template, virtual-access subinterfaces may be available. This feature also introduces a command to determine if a virtual template is compatible with virtual access subinterfaces.
Virtual Access Subinterfaces
The virtual-template command supports existing features, functions, and configurations. By default, the virtual-template subinterface command is enabled; this command cannot be disabled.
The virtual template manager will determine if the set of options configured on the virtual template are all supported on a subinterface. Virtual access subinterfaces will be created for all virtual templates that support subinterfaces. If the user has entered any commands that are not supported on a subinterface, a full virtual access interface is created and cloned for all PPP sessions using that virtual template.
Different applications can use the same virtual template even if one application is subinterface-capable and another is not. The virtual template manager is notified whether the application supports virtual access subinterfaces and creates the appropriate resource.
Virtual Template Compatibility with Subinterfaces
The test virtual-template subinterface privileged EXEC command determines whether a virtual template can support the creation of a virtual access subinterface. If the virtual template contains commands that prevent the creation of subinterfaces, the test virtual-template subinterface command identifies and displays these commands.
The debug vtemplate subinterface command displays debug messages that are generated if you enter configuration commands on the virtual template that are not valid on a subinterface. These messages are generated only if the debug vtemplate subinterface command is enabled, the virtual-template subinterface command is enabled, and a virtual template is configured that can support the creation of subinterfaces. If the creation of virtual access subinterfaces is disabled by the no virtual-template subinterface command, the debug vtemplate subinterface command produces no output.
Benefits of Broadband Scalability Features
Using broadband scalability reduces the amount of memory that is used per terminated PPP session by creating virtual access subinterfaces. These virtual access subinterfaces, along with improvements that are transparent to the user, speed up the cloning process.
How to Prepare for Broadband Access Aggregation
Configuring a Virtual Template Interface
Configure a virtual template interface before you configure PPPoE on an Ethernet interface. The virtual template interface is a logical entity that is applied dynamically as needed to an incoming PPP session request. Perform this task to create and configure a virtual template interface:
1.
enable
2.
configure
terminal
3.
Interface
virtual-template
number
[type [ethernet
|
serial
|
tunnel]]
4.
ip
unnumbered
ethernet
number
5.
mtu
bytes
6.
ppp
authentication
chap
7.
ppp
ipcp
ip
address
required
8. end
DETAILED STEPS
Examples
The following example shows the configuration of a virtual template interface:
Router(config)# interface virtual-template 1 Router(config)# ip unnumbered21 Loopback1 Router(config-if)# no peer default ip address Router(config-if)# ppp authentication chap Router(config-if)# ppp authorization Router(config-if)# ppp accounting
Configuring Enhancements for Broadband Scalability
To configure enhancement for broadband scalability, you will perform the following task:
Verifying Virtual Template Compatibility with Virtual Access Subinterfaces
Perform the following task to test a virtual template to determine if it is compatible with the creation of virtual access subinterfaces.
1.
enable
2.
test
virtual-template
template
subinterface
DETAILED STEPS
Examples
The output generated by the test virtual-template subinterface command describes the compatibility of the virtual template with the creation of subinterfaces.
This example shows output indicating that the virtual template is not compatible. This output also includes a list of the commands, which are configured on the virtual template, that cause the incompatibility.
Router# test virtual-template virtual-template1 subinterface Subinterfaces cannot be created using Virtual-Template1 Interface commands: traffic-shape rate 50000 8000 8000 1000
Configuration Examples for Preparing for Broadband Access Aggregation
Virtual Access Subinterfaces Configuration Examples
This section provides the following configuration examples:
- Virtual Access Subinterface Configuration Example
- Testing a Virtual Template for Compatibility with Subinterfaces Example
Virtual Access Subinterface Configuration Example
The example that follows shows a virtual template that is compatible with virtual access subinterfaces:
 Note | The virtual-access subinterface command is enabled by default and does not appear in running configurations. Only the no virtual-access subinterface command will appear in running configurations. |
interface Virtual-Template1 ip unnumbered Loopback0 peer default ip address pool pool-1 ppp authentication chap ppp multilink
The following example shows a configuration in which the creation of virtual access subinterfaces has been disabled by the no virtual-access subinterface command. When this command is configured, virtual access interfaces are not registered with the SNMP code on the router. In network environments that do not use SNMP to manage PPP sessions, this saves the memory and CPU processing that would be used to register the virtual access interfaces with the SNMP code.
Current configuration :6003 bytes ! ! Last configuration change at 10:59:02 EDT Thu Sep 19 2004 ! version 12.2 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption service internal service udp-small-servers service tcp-small-servers ! hostname ioswan5-lns ! enable password lab ! username cisco password 0 cisco clock timezone EST -5 clock summer-time EDT recurring aaa new-model ! ! aaa authentication ppp default local aaa authorization network default local aaa session-id common ip subnet-zero no ip gratuitous-arps ip cef ! ! no ip domain lookup ip name-server 10.44.11.21 ip name-server 10.44.11.206 ! ip vrf vpn1 rd 10:1 route-target export 10:1 route-target import 10:1 ! vpdn enable ! vpdn-group 1 accept-dialin protocol l2tp virtual-template 1 terminate-from hostname ioswan5-lac local name tunnel1 l2tp tunnel password 7 01100F175804 !
!
! no virtual-template subinterface no virtual-template snmp virtual-template 1 pre-clone 10 ! ! ! buffers small permanent 20000 buffers middle permanent 7500 ! ! ! interface Loopback1 ip address 10.111.1.1 255.255.255.0
Testing a Virtual Template for Compatibility with Subinterfaces Example
This example shows the process for testing a virtual template to determine if it can support virtual access subinterfaces. The following command displays the configuration for virtual template 1:
Router# show running interface virtual-template 1 Building configuration... ! interface Virtual-Template1 ip unnumbered Loopback0 peer default ip address pool pool-1 ppp authentication chap traffic-shape rate 50000 8000 8000 1000 end
The test virtual-template subinterface command tests virtual template 1 to determine if it can support subinterfaces. The output shows that the traffic-shape rate command that is configured on virtual template 1 prevents the virtual template from being able to support subinterfaces.
Router# test virtual-template 1 subinterface Subinterfaces cannot be created using Virtual-Template1 Interface commands: traffic-shape rate 50000 8000 8000 1000
Additional References
The following sections provide references related to preparing for broadband access aggregation.
Related Documents
Standards
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Standards |
Title |
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No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
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MIBs
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MIBs |
MIBs Link |
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No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS XE releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
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RFCs |
Title |
|---|---|
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No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
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Technical Assistance
|
Description |
Link |
|---|---|
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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. |
Feature Information for Preparing for Broadband Access Aggregation
The following table provides release information about the feature or features described in this module. This 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.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.|
Feature Name |
Software Releases |
Feature Configuration Information |
|---|---|---|
|
Virtual Sub-Interface--Configuration Enhancements for Broadband Scalability |
Cisco IOS XE Release 2.1 |
This feature was introduced on Cisco ASR 1000 Series Routers. This feature reduces the amount of memory that is used per terminated PPP session by creating virtual access subinterfaces. Depending on the configuration of the source virtual template, virtual access subinterface may be available. This feature also introduces a command to determine if a virtual template is compatible with virtual access subinterfaces. |
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