PPP IP Unique Address and Prefix Detection
First Published: November 24, 2010
Last Updated: November 24, 2010
The PPP IP Unique Address and Prefix Detection feature checks the uniqueness of IPv4 address and IPv6 prefix on the Broadband Remote Access Server (BRAS). PPP disconnects the session if it detects a duplicate IPv4 address and IPv6 prefix.
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 for PPP IP Unique Address and Prefix Detection" section.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•"Information About PPP IP Unique Address and Prefix Detection" section
•"How to Configure PPP IP Unique Address and Prefix Detection" section
•"Configuration Examples for PPP IP Unique Address and Prefix Detection" section
•"Additional References" section
•"Feature Information for PPP IP Unique Address and Prefix Detection" section
Information About PPP IP Unique Address and Prefix Detection
•IPv6 checks if the prefix is unique when it is installed on an interface. If the prefix installation fails, PPP disconnects the session.
•PPP also checks if the IPv4 address is unique. PPP disconnects the session if a duplicate IPv4 address is detected.
How to Configure PPP IP Unique Address and Prefix Detection
Perform this task to configure the PPP IP Unique Address and Prefix Detection feature.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface virtual-template interface-number
4. ppp ipcp address required
5. ppp ipcp address unique
6. ppp ipv6cp address unique
7. ppp timeout ncp seconds
8. exit
9. ppp ncp override local
10. end
DETAILED STEPS
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Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
interface virtual-template interface-number
Router(config)# interface virtual-template 7 |
Selects the Virtual Template interface and enters interface configuration mode. |
Step 4 |
ppp ipcp address required
Router(config-if)# ppp ipcp address required |
PPP disconnects the peer if no IP address is negotiated. |
Step 5 |
ppp ipcp address unique
Router(config-if)# ppp ipcp address unique |
PPP disconnects the peer if the IP address is already in use. |
Step 6 |
ppp ipv6cp address unique
Router(config-if)# ppp ipv6cp address unique |
PPP disconnects the peer if the IPv6 prefix is already in use. |
Step 7 |
ppp timeout ncp seconds
Router(config-if)# ppp timeout ncp 30 |
PPP sets the maximum time in seconds to wait for the network layer to negotiate. |
Step 8 |
exit
Router(config-if)# exit |
Exits interface configuration mode and returns to global configuration mode. |
Step 9 |
ppp ncp override local
Router(config)# ppp ncp override local |
PPP overrides the local dual-stack configuration, checks the permitted Network Control Programs (NCP), and rejects user-initiated NCP negotiation. |
Step 10 |
end
Router(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
Configuration Examples for PPP IP Unique Address and Prefix Detection
This section provides the following configuration example:
•Example: PPP Unique Address and Prefix Detection
Example: PPP Unique Address and Prefix Detection
To enable the PPP IP Unique Address nd Prefix Detection feature, use the following configuration.
Router# configure terminal
Router(config)# interface virtual-template 7
Router(config-if)# ppp ipcp address required
Router(config-if)# ppp ipcp address unique
Router(config-if)# ppp ipv6cp address unique
Router(config-if)# ppp timeout ncp 30
Router(config)# ppp ncp override local
Additional References
Related Documents
Standards
MIBs
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None |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs |
RFCs
Technical Assistance
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The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
http://www.cisco.com/cisco/web/support/index.html |
Feature Information for PPP IP Unique Address and Prefix Detection
Table 1 lists the release history for this feature.
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://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 1 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.
Table 1 Feature Information for PPP IP Unique Address and Prefix Detection
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PPP IP Unique Address and Prefix Detection |
Cisco IOS XE Release 3.2S |
The PPP IP Unique Address and Prefix Detection feature checks the uniqueness of IPv4 address and IPv6 prefix on the BRAS. PPP disconnects the session if it detects a duplicate IPv4 address and IPv6 prefix. The following commands were introduced: ppp ipv6cp address unique, ppp ncp override local. |
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