- IPv6 Addressing and Basic Connectivity
- IPv6 Anycast Address
- IPv6 Switching: Cisco Express Forwarding and Distributed Cisco Express Forwarding Support
- Unicast Reverse Path Forwarding for IPv6
- IPv6 Services: AAAA DNS Lookups over an IPv4 Transport
- IPv6 MTU Path Discovery
- ICMP for IPv6
- ICMP for IPv6 Redirect
- IPv6 Neighbor Discovery
- IPv6 Neighbor Discovery Cache
- Enhanced IPv6 Neighbor Discovery Cache Management
- IPv6 Default Router Preference
- IPv6 Stateless Autoconfiguration
- IPv6 RFCs
IPv6 Neighbor Discovery Cache
The IPv6 neighbor discovery cache feature allows static entries to be made in the IPv6 neighbor cache.
The per-interface neighbor discovery cache limit function can be used to prevent any particular customer attached to an interface from overloading the neighbor discovery cache, whether intentionally or unintentionally.
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 at the end of this module.
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.
Information About IPv6 Static Cache Entry for Neighbor Discovery
IPv6 Neighbor Discovery
The IPv6 neighbor discovery process uses ICMP messages and solicited-node multicast addresses to determine the link-layer address of a neighbor on the same network (local link), verify the reachability of a neighbor, and track neighboring devices.
The IPv6 static cache entry for neighbor discovery feature allows static entries to be made in the IPv6 neighbor cache. Static routing requires an administrator to manually enter IPv6 addresses, subnet masks, gateways, and corresponding Media Access Control (MAC) addresses for each interface of each device into a table. Static routing enables more control but requires more work to maintain the table. The table must be updated each time routes are added or changed.
Per-Interface Neighbor Discovery Cache Limit
The number of entries in the Neighbor Discovery cache can be limited by interface. Once the limit is reached, no new entries are allowed. The per-interface Neighbor Discovery cache limit function can be used to prevent any particular customer attached to an interface from overloading the Neighbor Discovery cache, whether intentionally or unintentionally.
When this feature is enabled globally, a common per-interface cache size limit is configured on all interfaces on the device. When this feature is enabled per interface, a cache size limit is configured on the associated interface. The per-interface limit overrides any globally configured limit.
How to Configure IPv6 Neighbor Discovery Cache
- Configuring a Neighbor Discovery Cache Limit on a Specified Device Interface
- Configuring a Neighbor Discovery Cache Limit on All Device Interfaces
Configuring a Neighbor Discovery Cache Limit on a Specified Device Interface
DETAILED STEPS
Configuring a Neighbor Discovery Cache Limit on All Device Interfaces
DETAILED STEPS
Configuration Examples for IPv6 Neighbor Discovery Cache
Example: Verifying a Neighbor Discovery Cache Limit Configuration
Device# show ipv6 interface Ethernet2/0
Interface Ethernet2/0, entries 2, static 0, limit 4
IPv6 Address Age Link-layer Addr State Interface
2001:0db8::93 0 aabb.cc00.5d02 REACH Et2/0
FE80::A8BB:CCFF:FE00:5D02 0 aabb.cc00.5d02 DELAY Et2/0
Additional References
Related Documents
| Related Topic | Document Title |
|---|---|
| IPv6 addressing and connectivity |
IPv6 Configuration Guide |
| Cisco IOS commands |
|
| IPv6 commands |
Cisco IOS IPv6 Command Reference |
| Cisco IOS IPv6 features |
Cisco IOS IPv6 Feature Mapping |
Standards and RFCs
| Standard/RFC | Title |
|---|---|
| RFCs for IPv6 |
IPv6 RFCs |
MIBs
| MIB |
MIBs Link |
|---|---|
| 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 releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
| 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. |
Feature Information for IPv6 Neighbor Discovery Cache
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.
| Table 1 | Feature Information for IPv6 Neighbor Discovery Cache |
| Feature Name | Releases | Feature Information |
|---|---|---|
| IPv6: Per-Interface Neighbor Discovery Cache Limit |
15.1(1)SY 15.1(3)T Cisco IOS XE Release 2.6 |
The per-interface neighbor discovery cache limit function can be used to prevent any particular customer attached to an interface from overloading the neighbor discovery cache, whether intentionally or unintentionally. The following commands were introduced or modified: ipv6 nd cache interface-limit, show ipv6 interface. |
| IPv6 Static Cache Entry for Neighbor Discovery |
12.2(8)T 12.2(17)SX1 12.2(25)SEA 12.2(25)SG 12.2(33)SRA Cisco IOS XE Release 2.1 15.0(2)SG 3.2.0SG |
The IPv6 static cache entry for Neighbor Discovery feature allows static entries to be made in the IPv6 neighbor cache. The following commands were introduced or modified: ipv6 nd cache interface-limit, show ipv6 interface. |
Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.
Feedback