Information About IPv6 Addressing and Basic Connectivity Because RFC 3879 obsoletes the use of site-local addresses, configuration of private IPv6 addresses should be done following the recommendations of unique local addressing (ULA) in RFC 4193.

However, multiple IPv6 link-local addresses on an interface are not supported.

Multiple IPv6 global addresses within the same prefix can be configured on an interface.

Therefore, IPv6 hosts can be directly attached to Layer 2 LAN devices. IPv6 packets are transparent to Layer 2 LAN devices because the devices do not examine Layer 3 packet information before forwarding IPv6 frames. Restrictions for IPv6 Addressing and Basic Connectivity To access Cisco Feature Navigator, go to An account on is not required. Use Cisco Feature Navigator to find information about platform support and Cisco software image support. 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. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. Your software release may not support all the features documented in this module. The user can enhance basic connectivity functionality by configuring support for AAAA record types in the Domain Name System (DNS) name-to-address and address-to-name lookup processes, and by managing IPv6 neighbor discovery. IPv6 traffic forwarding can be enabled globally, and Cisco Express Forwarding switching for IPv6 can also be enabled. Implementing basic IPv6 connectivity in the Cisco software consists of assigning IPv6 addresses to individual device interfaces. The unlimited address space provided by IPv6 allows Cisco to deliver more and newer applications and services with reliability, improved user experience, and increased security. Internet Protocol version 6 (IPv6) expands the number of network address bits from 32 bits (in IPv4) to 128 bits, which provides more than enough globally unique IP addresses for every networked device on the planet.

Feature Information for IPv6 Addressing and Basic Connectivity.Example: Hostname-to-Address Mappings Configuration.Example: Dual-Protocol Stack Configuration.Example: IPv6 Addressing and IPv6 Routing Configuration.Configuration Examples for IPv6 Addressing and Basic Connectivity.

Configuring an Interface to Support the IPv4 and IPv6 Protocol Stacks.Configuring IPv6 Addressing and Enabling IPv6 Routing.How to Configure IPv6 Addressing and Basic Connectivity.IPv6 on BVI Interfaces for Bridging and Routing.IPv6 for Cisco Software Support for Wide-Area Networking Technologies.Cisco Discovery Protocol IPv6 Address Support.Large IPv6 Address Space for Unique Addresses.Information About IPv6 Addressing and Basic Connectivity.Restrictions for IPv6 Addressing and Basic Connectivity.

Rules for compressing ipv6 addresses