Cisco IOS Router IPv6
Most of Cisco’s IOS based routers support IPv6 with the right IOS version. This page compiles basic information on the various IPv6 capabilities the main line IOS version have, based on Cisco documentation and compliance tests of the Defense Information Systems Agency/Joint Interoperability Test Command (JITC) on their Approved Product List. Since IOS releases generally have the same feature set across different routers and product families the remarks here should apply to other Cisco systems running the same IOS versions as well.
The Further reading section has many documents and links to resources for details on IPv6 configuration and commands on Cisco IOS.
| Content from | July 2009, sourced: June 2007-June 2008 |
|---|---|
| Current version | N/A |
| Documented version | Cisco IOS 12.4; 12.3; 12.xT from 12.2T and up |
| Documentation for | Cisco IOS 12.4 |
Basic IPv6 functions
Overview
IPv6 is active in default, vanilla IOS releases that support it. However, IPv6 routing is deactivated by default and must be manually switched on. The integrated routing and advertisement daemon is active by default after manual address and prefix configuration.
For command references for IPv6 Cisco has a very good IPv6 Command Reference book, see the Further reading section.
Preference
If and when Cisco IOS prefers IPv6 over IPv4 could not be stated definately after studying the documentation.
Privacy Extensions
It seems privacy extensions for host adresses are not supported in Cisco IOS, the documentation does not mention the corresponding RFCs.
Packet Filter/Firewall
Both filtering/firewalling solutions on IOS support IPv6:
- Access control lists (ACLs):
Cisco IOS can filter IPv6 packets with its integrated Access Control Lists (ACLs).
The filtering is stateful for IPv6 and supported since 12.2(2)T and 12.3.
Tunnelled and translated packets can also be filtered. - Cisco IOS Firewall: supports IPv6 filtering since IOS 12.3(7)T and 12.4.
For a reference and configuration guide on the firewalls, see Firewall.
Data link
Cisco IOS supports a variety of IPv6 over data link layers, including:
- Ethernet (Ethernet, Fast Ethernet, Gigabit Ethernet, and 10-Gigabit Ethernet)
- Frame Relay
- PPPv6
- HLDCP
- ATM
- FDDI
- MPLS/6PE
Tunnelling IPv4/IPv6
For a reference and configuration guide on each of these tunnels, see Tunnelling.
Configured tunnels
Cisco IOS supports configured IPv6 tunnels.
6to4
Interfaces support 6to4 prefixes and routing in Cisco IOS after manual configuring them to do so.
Other tunnels
Cisco IOS supports many more IPv6 and related tunneling types and strategies, which are not discussed here in depth. These include:
- IPv6 IPsec VPNs are supported in IOS since 12.4(4)T
- 6PE, IPv6 over IPv6 MPLS VPNs
- ISATAP
- GRE
DHCPv6
Cisco IOS integrates DHCPv6 server, client and relay [from 12.3(11)T and 12.4] functionality. The different software parts have to be enabled and configured separately. They support both DHCPv6 modes of operation, stateless DHCPv6 and stateful DHCPv6 with configuration of the following parameters:DHCPv6
- Unique global addresses configuration, from versions 12.4(24)T
- Stateless addresses, from 12.3(4)T, 12.4 and 12.4(2)T
- Prefix delegation (PD), from 12.3(4)T, 12.4 and 12.4(2)T
- DNS server address, from 12.4(15)T
- NTP server address, from 12.4(15)T
- NIS server address, from 12.4(15)T
- SIP server address, from 12.4(15)T
- Domain name, from 12.3(4)T, 12.4 and 12.4(2)T
- Information refresh option, from 12.4(15)T
- Relay ID option
The following IETF DHCPv6 RFCs are supported:
| Document | Title |
|---|---|
| RFC3315 | Dynamic Host Configuration Protocol for IPv6 (DHCPv6) |
| RFC3319 | Dynamic Host Configuration Protocol (DHCPv6) Options for Session Initiation Protocol (SIP) Servers |
| RFC3633 | IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) |
| RFC3646 | DNS Configuration options for Dynamic Host Configuration Protocol for IPv6 (DHCPv6) |
| RFC3898 | NIS server option, NIS domain option/NIS+ server option, NIS+ domain option |
| RFC4075 | Simple Network Time Protocol (SNTP) Configuration Option for DHCPv6 |
| RFC4242 | Information Refresh Time Option for Dynamic Host Configuration Protocol for IPv6 (DHCPv6) |
| RFC4649 | DHCPv6 Relay Agent Remote-ID Option |
PPPv6
IPv6 PPP (PPPv6) is supported in IOS over various data link layers, both broadband and serial. There are multiple ways to support PPPv6 server and client mode, depending on the type of underlying connection and authentication types. PPPv6 is supported since 12.2(13)T and 12.3 (both PPPoE and PPPoA, and PPP over serial, SONET and ISDN).PPPv6
Routing
Cisco IOS supports most dynamic IPv6 routing protocols, including:Routing
- RIPng (RIP over IPv6), from 12.2(2)5T and 12.3
- MP BGP over IPv6 (BGPv6), from 12.2(2)6T and 12.3
- IS-IS for IPv6, from 12.2(8)T and 12.3
- OSPF for IPv6 (OSPFv3), from 12.2(15)T and 12.3
- EIGRP IPv6 support, from 12.4(6)T
This list is not exhaustive.
Management
Most device and network management services and protocols support IPv6 in Cisco IOS:
- SSH over IPv6 server and client
- Telnet over IPv6 server and client
- TFTP upload and download over IPv6
- SNMP over IPv6
- Syslog over IPv6
Supported IPv6 RFCs & IDs
There are two tables with supported Cisco IOS IPv6 supported RFCs: the first (Table 2) is compiled from the DISA JITC compliance tests, the second (Table 3) from Cisco documentation.
| Document | Title |
|---|---|
| RFC 1981 | Path MTU discovery for IP version 6 |
| RFC 2460 | Internet protocol, version 6 (IPv6) specification |
| RFC 2461 | Neighbor discovery for IP version 6 (IPv6) |
| RFC 2462 | IPv6 stateless address autoconfiguration |
| RFC 2464 | Transmission of IPv6 packets over Ethernet networks |
| RFC 2472 | PPPv6 |
| RFC 2492 | IPv6 over ATM networks |
| RFC 2590 | IPv6 over Frame Relay |
| RFC 2710 | Multicast Listener Discovery (MLD) for IPv6 |
| RFC 3315 | Stateful DHCPv6 |
| RFC 3484 | Default Address selection |
| RFC 3810 | Multicast Listener Discovery Version 2 (MLDv2) |
| RFC 4007 | IPv6 Scoped Address Architecture |
| RFC 4193 | Unique Local IPv6 Unicast Addresses |
| RFC 4213 | Transition Mechanisms for IPv6 Host and Routers |
| RFC 4291 | IPv6 Addressing Architecture |
| RFC 4443 | Internet Control Message Protocol (ICMPv6) for the Internet ProtoVersion 6 (IPv6) Specification |
The following list was compiled from Cisco’s own product documentation, but is also not exhaustive.
| Document | Title |
|---|---|
| RFC 1981 | Path MTU discovery for IP version 6 |
| RFC 2080 | RIPng for IPv6 |
| RFC 2373 | IPv6 Addressing |
| RFC 2374 | IPv6 Aggregatable Global Unicast Address Format |
| RFC 2460 | Internet protocol, version 6 (IPv6) specification |
| RFC 2461 | Neighbor discovery for IP version 6 (IPv6) |
| RFC 2462 | IPv6 stateless address autoconfiguration |
| RFC 2463 | Internet Control Message Protocol (ICMPv6) for IPv6 |
| RFC 2464 | Transmission of IPv6 packets over Ethernet networks |
| RFC 2467 | Transmission of IPv6 Packets over FDDI Networks |
| RFC 2472 | PPPv6 |
| RFC 2473 | Generic packet Tunneling in IPv6 |
| RFC 2474 | Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers |
| RFC 2492 | IPv6 over ATM Networks |
| RFC 2545 | Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing |
| RFC 2590 | Transmission of IPv6 Packets over Frame Relay Networks Specification |
| RFC 2740 | OSPF for IPv6 |
| RFC 2765 | Stateless IP/ICMP Translation Algorithm (SIIT) |
| RFC 2766 | Network Address Translation - Protocol Translation (NAT-PT) |
| RFC 2858 | Multiprotocol Extensions for BGP-4 |
| RFC 2893 | Transition Mechanisms for IPv6 Hosts and Routers (automatic and configured tunnels) |
| RFC 3056 | Connection of IPv6 Domains via IPv4 Clouds |
| RFC 3152 | Delegation of IP6.ARPA |
| RFC 3162 | RADIUS and IPv6 |
| RFC 3177 | IAB/IESG Recommendations on IPv6 Address |
| RFC 3315 | Stateful DHCPv6 |
| RFC 3319 | Dynamic Host Configuration Protocol (DHCPv6) Options for Session Initiation Protocol (SIP) Servers |
| RFC 3513 | Internet Protocol Version 6 (IPv6) Addressing Architecture |
| RFC 3596 | DNS Extensions to support IPv6 |
| RFC 3633 | IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) Version 6 |
| RFC 3646 | DNS Configuration Options for Dynamic Host Configuration Protocol for IPv6 (DHCPv6) |
| RFC 3736 | Stateless DHCP Service for IPv6 |
| RFC 3775 | Mobility Support in IPv6 |
| RFC 3810 | Multicast Listener Discovery Version 2 (MLDv2) |
| RFC 3879 | Deprecating Site Local Addresses |
| RFC 3898 | Network Information Service (NIS) Configuration Options for Dynamic Host Configuration Protocol for IPv6 (DHCPv6) |
| RFC 3963 | Network Mobility (NEMO) Basic Support Protocol |
| RFC 4007 | IPv6 Scoped Address Architecture |
| RFC 4075 | Simple Network Time Protocol (SNTP) Configuration Option for DHCPv6 |
| RFC 4193 | Unique Local IPv6 Unicast Addresses |
| RFC 4214 | Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) |
| RFC 4242 | Information Refresh Time Option for Dynamic Host Configuration Protocol for IPv6 (DHCPv6) |
| RFC 4282 | The Network Access Identifier |
| RFC 4283 | Mobile Node Identifier Option for Mobile IPv6 (MIPv6) |
| RFC 4285 | Authentication Protocol for Mobile IPv6 |
| RFC 4291 | IP Version 6 Addressing Architecture |
| RFC 4364 | BGP MPLS/IP Virtual Private Networks (VPNs) |
| RFC 4443 | Internet Control Message Protocol for IPv6 (ICMPv6) |
| RFC 4584 | Extension to Sockets API for Mobile IP |
| RFC 4649 | Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Relay Agent Remote-ID Option |
| RFC 4659 | BGP-MPLS IP Virtual Private Network (VPN) Extension for IPv6 VPN |
| RFC 4798 | Connecting IPv6 Islands over IPv4 MPLS Using IPv6 Provider Edge Routers (6PE) |
| RFC 4941 | Privacy Extensions for Stateless Address Autoconfiguration in IPv6 |
| RFC 5095 | Deprecation of Type 0 Routing Headers in IPv6 |
References
- [DHCPv6] Implementing DHCP for IPv6 Cisco IOS IPv6 Configuration Guide Release 12.4 (Cisco Systems, Inc: 2009. Accessed July 2009) and Cisco IOS IPv6 Configuration Guide Release 12.4 pp.41—42 (Cisco Systems, Inc: August 2008. Accessed July 2009) ↑
- [DHCPv6-RFC] Implementing DHCP for IPv6: RFCs (Cisco Systems, Inc: 2009. Accessed July 2009) ↑
- [PPPv6] Implementing ADSL and Deploying Dial Access for IPv6 Cisco IOS IPv6 Configuration Guide Release 12.4 (Cisco Systems, Inc: August 2008. Accessed July 2009) ↑
- [Firewall] Implementing Traffic Filters and Firewalls for IPv6 Security (Cisco Systems, Inc: August 2008. Accessed July 2009) and Creating and Configuring an IPv6 ACL for Traffic Filtering (Cisco Systems, Inc: August 2008. Accessed July 2009) ↑
- [Tunnelling] Implementing Tunneling for IPv6 Cisco IOS IPv6 Configuration Guide Release 12.4 (Cisco Systems, Inc: August 2008. Accessed July 2009) ↑
- [Routing] Cisco IOS IPv6 Configuration Guide Release 12.4 pp.35—37 (Cisco Systems, Inc: August 2008. Accessed July 2009) ↑
- [RFC JITC] Cisco 2800 Series IPv6 Letter of Compliance for DISA/JITC (Cisco Systems, Inc: June 2007. Accessed July 2009) ↑
- [RFC Cisco] Table compiled from individual sections in Cisco IOS IPv6 Configuration Guide Release 12.4 (Cisco Systems, Inc: August 2008. Accessed July 2009) ↑
Further reading
- Cisco IOS IPv6 Command Reference (Cisco Systems: 2009)
- Book version (PDF) Cisco IOS IPv6 Command Reference (Cisco Systems: June 2009) [19MB PDF, 1800 pages]
- Cisco IOS IPv6 Configuration Guide, Release 12.4 (Cisco Systems: 2009)
- Book version (PDF) Cisco IOS IPv6 Configuration Guide Release 12.4 (Cisco Systems, Inc: August 2008. Accessed July 2009) has detailed chapters with configuration examples on almost all protocols. The table from pp.31—48 has quick links to the online version of the individual chapters.