The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.
The PPP IP Unique Address and Prefix Detection feature checks the uniqueness of IPv4 addresses and IPv6 prefixes on the broadband remote access server (BRAS). PPP disconnects the session if it detects a duplicate IPv4 address and IPv6 prefix.
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.
Perform this task to configure the PPP IP Unique Address and Prefix Detection feature.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface virtual-template interface-number Example: |
Selects the Virtual Template interface and enters interface configuration mode. |
|
Step 4 |
ppp ipcp address required Example: |
PPP disconnects the peer if no IP address is negotiated. |
|
Step 5 |
ppp ipcp address unique Example: |
PPP disconnects the peer if the IP address is already in use. |
|
Step 6 |
ppp ipv6cp address unique Example: |
PPP disconnects the peer if the IPv6 prefix is already in use. |
|
Step 7 |
ppp timeout ncp seconds Example: |
PPP sets the maximum time in seconds to wait for the network layer to negotiate. |
|
Step 8 |
exit Example: |
Exits interface configuration mode and returns to global configuration mode. |
|
Step 9 |
ppp ncp override local Example: |
PPP overrides the local dual-stack configuration, checks the permitted Network Control Programs (NCP), and rejects user-initiated NCP negotiation. |
|
Step 10 |
end Example: |
Exits global configuration mode and returns to privileged EXEC mode. |
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-if)# exit
Router(config)# ppp ncp override local
Router(config)# end
|
Related Topic |
Document Title |
|---|---|
|
Broadband Access Aggregation and DSL commands |
Cisco IOS Broadband Access Aggregation and DSL Command Reference |
|
Standard |
Title |
|---|---|
|
None |
-- |
|
MIB |
MIBs Link |
|---|---|
|
None |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
|
RFC |
Title |
|---|---|
|
None |
-- |
|
Description |
Link |
|---|---|
|
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. |
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 |
Releases |
Feature Information |
|---|---|---|
|
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 . |
Feedback