This chapter provides an overview of the standardized solutions to make the transition from ipv4 to ipv6. Interface and hardware component configuration guide, cisco ios release 15s 4 ipv6 automatic ipv4 compatible tunnels automatic ipv4 compatible ipv6 tunnels. With an ipv4compatible tunnel, the tunnel destination is automatically determined by the ipv4 address in the loworder 32 bits of ipv4compatible ipv6 addresses. Automatic tunnels require ipv4 compatible addresses. Ipv6 sites or hosts connected using this method do not require ipv4 compatible ipv6 addresses or configured tunnels. Rfc 2529 transmission of ipv6 over ipv4 domains without explic. With ipv4, this means that each packet has a 32bit source address and a 32bit destination address in the layer 3 header. How to configure ipv6 automatic ipv4compatible tunnels configuring ipv4compatible ipv6 tunnels, page 4. The reason that a 6to4 tunnel and an ipv4 compatible tunnel cannot share an interface is that both of them are nbma pointtomultipoint access links and only the tunnel source can be used to reorder the packets from a multiplexed packet stream into.
One of the biggest limitations with ipv4compatible ipv6 tunnels is the fact that they do not support connection to the native ipv6 internet. We want to leverage what we have built the pointtopoint transfer of packets over a serial line network into an arbitrarily larger network, an internet. Interface and hardware component configuration guide, cisco ios release 15s 4 ipv6 automatic ipv4compatible tunnels automatic ipv4compatible ipv6 tunnels. The tunnels may be managed with the tunnel setup protocol tsp or ayiya. An automatic 6to4 tunnel allows isolated ipv6 domains to be connected over an ipv4 network to other isolated ipv6 networks. This establishes ipv6 tunnels within the ipv4 internet. One of the key difference between automatic 6to4 tunnels vs manually configured tunnels is that the tunnel itself is not a pointtopoint, but rather a pointtomultipoint tunnel. The use case is also to allow ipv6 domains connected to a wide area network with no native ipv6 support to communicate with each other. Rfc 2893 transition mechanisms for ipv6 hosts and routers. Tunneling provides a way to use an existing ipv4 routing infrastructure to carry ipv6 traffic. Automatic ipv4 compatible tunnels this kind of tunnel uses ipv4 compatible ipv6 addresses for tunnel interfaces. Chapter 4 making the transition from ipv4 to ipv6 reference. But, when setting up a ip route using metric 1 the.
The tunnels always terminate on the dualstack host. Automatic tunnels require ipv4compatible addresses. Rfc 2529 transmission of ipv6 over ipv4 domains without. These tunnels can originate either on a dualstack host or on a dualstack router by configuring an automatic tunneling network interface.
Tunneling technologies be the packets ccie study blog. Ipv4compatible tunnels can be configured between borderrouters or between a borderrouter and a host. An ipv6 address format that employs embedded ipv4 addresses. At the network layer, the packets of the communication need to be identified with the source and destination addresses of the two end systems.
Interface and hardware component configuration guide. For ipv4 compatible ipv6 tunnels to work, the communicating nodes must both support automatic tunneling. In particular it allows a site to run both ipv4 and ipv6 in coexistence, without having to configure ipv6 hosts either with ipv4 compatible addresses or with tunnels. In particular it allows a site to run both ipv4 and ipv6 in coexistence, without having to configure ipv6 hosts either with ipv4compatible addresses or with tunnels. How to configure ipv6 automatic ipv4compatible tunnels configuring ipv4compatible ipv6 tunnels performthistasktoconfigureipv4compatibleipv6tunnels. The ipv6 over ipv4 mechanism is intended to take its place in the range of options available for transition from ipv4 to ipv6. Using ipv4compatible tunnels is an easy method to create tunnels for ipv6 over ipv4, but the technique does not scale for large networks. One of the biggest limitations with ipv4 compatible ipv6 tunnels is the fact that they do not support connection to the native ipv6 internet. Jan 19, 2018 the reason that a 6to4 tunnel and an ipv4 compatible tunnel cannot share an interface is that both of them are nbma pointtomultipoint access links and only the tunnel source can be used to reorder the packets from a multiplexed packet stream into a single packet stream for an incoming interface. Automatic tunnels can be used to connect ipv6 nodes when ipv6 routers are not available. For ipv4compatible ipv6 tunnels to work, the communicating nodes must both. Hosts that are capable of automatic tunneling use special ipv6 addresses. The host or router at each end of an ipv4compatible tunnel must support both the ipv4 and ipv6 protocol stacks. Chapter 4 making the transition from ipv4 to ipv6 reference when hosts and routers are upgraded to ipv6, these nodes now have to interoperate with the ipv4 hosts and ipv4 routers.
Building internets once we have a way to convert names to addresses, we can start thinking of ways to have more than two systems in a network. Introduction to ipv6 philip smith apricot 20 singapore 19th feb 1st march 20. Rfc 7059 a comparison of ipv6overipv4 tunnel mechanisms. The anatomy of an ipv4 address each device on a network must be uniquely defined. Pointtomultipointtunnelsthatcan beusedtoconnectisolatedipv6 sites. With ipv4, this means that each packet has a 32bit source address and a 32. Jung 3com march 1999 transmission of ipv6 over ipv4 domains without explicit tunnels status of this memo this document specifies an internet standards track protocol for the internet community, and requests discussion and suggestions for improvements. How to configure ipv6 automatic ipv4compatible tunnels. These addresses are taken from 96 address comprised of the first 96 bits containing all zeros and the last 32 bits are derived from the ipv4 address. Late 1980s exponential growth of the internet late 1990. Automatic tunnels ipv6 administration guide oracle docs. Ipv4compatible ipv6 tunnels were initially specified in rfc 2893, along with.
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