1. 6to4 https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

2. IPv6 rapid deployment - Comparison to 6to4 1 With 6rd, this model is changed by making each ISP use one of its own IPv6 prefixes instead of the special 2002::/16 prefix standardized for 6to4 https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

3. IPv6 rapid deployment - Comparison to 6to4 1 Because 6rd relays can only be used by a limited set of hosts that are all under the control of the same administrative entity, it also reduces the scope for traffic anonymization attacks such as those possible with 6to4. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

4. 6to4 1 '6to4' is an Internet IPv6#Transition mechanisms|transition mechanism for migrating from IPv4 to IPv6, a system that allows IPv6 packets to be transmitted over an IPv4 network (generally the IPv4 Internet) without the need to configure explicit tunneling protocol|tunnels. Special relay servers are also in place that allow 6to4 networks to communicate with native IPv6 networks. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

5. 6to4 1 6to4 is especially relevant during the initial phases of deployment to full, native IPv6 connectivity, since IPv6 is not required on nodes between the host and the destination. However, it is intended only as a transition mechanism and is not meant to be used permanently. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

6. 6to4 1 6to4 may be used by an individual host, or by a local IPv6 network. When used by a host, it must have a global IPv4 address connected, and the host is responsible for encapsulation of outgoing IPv6 packets and decapsulation of incoming 6to4 packets. If the host is configured to forward packets for other clients, often a local network, it is then a router. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

7. 6to4 1 A 6to4 router will know to send an encapsulated packet directly over IPv4 if the first 16 bits are 2002, using the next 32 as the destination, or otherwise send the packet to a well-known relay server, which has access to native IPv6. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

8. 6to4 1 6to4 does not facilitate interoperation between IPv4-only hosts and IPv6-only hosts. 6to4 is simply a transparent mechanism used as a transport layer between IPv6 nodes. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

9. 6to4 1 Due to the high levels of misconfigured hosts and poor performance observed, an advisory about how 6to4 should be deployed was published in August 2011.RFC 6343 - Advisory Guidelines for 6to4 Deployment https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

10. 6to4 - How 6to4 works 1 * Routes traffic between 6to4 and native IPv6 networks. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

11. 6to4 - Address block allocation 1 For any 32-bit global IPv4 address that is assigned to a host, a 48-bit 6to4 IPv6 prefix can be constructed for use by that host (and if applicable the network behind it) by appending the IPv4 address to 2002::/16. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

12. 6to4 - Address block allocation 1 For example the global IPv4 address 192.0.2.4 has the corresponding 6to4 prefix 2002:c000:0204::/48. This gives a prefix length of 48 bits, which leaves room for a 16-bit subnet field and 64 bit host addresses within the subnets. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

13. 6to4 - Address block allocation 1 Any IPv6 address that begins with the 2002::/16 prefix (in other words, any address with the first two octets of 2002 hexadecimal) is known as a '6to4 address', as opposed to a native IPv6 address which does not use transition technologies. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

14. 6to4 - Encapsulation and transmission 1 The IPv4 destination address for the prepended packet header is derived from the IPv6 destination address of the inner packet (which is in the format of a 6to4 address), by extracting the 32 bits immediately following the IPv6 destination address's 2002::/16 prefix https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

15. 6to4 - Routing between 6to4 and native IPv6 1 To allow hosts and networks using 6to4 addresses to exchange traffic with hosts using native IPv6 addresses, relay routers have been established. A relay router connects to an IPv4 network and an IPv6 network. 6to4 packets arriving on an IPv4 interface will have their IPv6 payloads routed to the IPv6 network, while packets arriving on the IPv6 interface with a destination address prefix of 2002::/16 will be encapsulated and forwarded over the IPv4 network. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

16. 6to4 - Routing between 6to4 and native IPv6 1 There is a difference between a relay router and a border router (also known as a 6to4 border router). A 6to4 border router is an IPv6 router supporting a 6to4 pseudo-interface. It is normally the border router between an IPv6 site and a wide-area IPv4 network, where the IPv6 site uses 2002::/16 co-related to the IPv4 address used later on. On the other hand, a relay router is a 6to4 router configured to support transit routing between 6to4 addresses and pure native IPv6 addresses. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

17. 6to4 - Routing between 6to4 and native IPv6 1 Providers willing to provide 6to4 service to their clients or peers should advertise the anycast prefix like any other IP prefix, and route the prefix to their 6to4 relay. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

18. 6to4 - Routing between 6to4 and native IPv6 1 Packets from the IPv6 Internet to 6to4 systems must be sent to a 6to4 relay router by normal IPv6 routing methods. The specification states that such relay routers must only advertise 2002::/16 and not subdivisions of it to prevent IPv4 routes polluting the routing tables of IPv6 routers. From here they can then be sent over the IPv4 Internet to the destination. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

19. 6to4 - Routing between 6to4 and native IPv6 1 A variant called IPv6 rapid deployment (6rd) uses the same basic principles as 6to4 but uses a relay operated by the 6rd user's ISP for traffic in both directions https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

20. 6to4 - Reverse DNS delegation 1 When a site using 6to4 has a fixed global IPv4 address, its 6to4 IPv6 prefix is also fixed. It is then possible to request reverse DNS delegation for an individual 6to4 48- bits prefix inside the 2.0.0.2.ip6.arpa DNS zone from the Number Resource Organization at [http://6to4.nro.net/]. The process is entirely automatic. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

21. 6to4 - Security considerations 1 According to RFC 3964, 6to4 routers and relays should ensure that: https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

22. 6to4 - Security considerations 1 * either or both the source and destination addresses of any encapsulated packet is within the 6to4 IPv6 prefix 2002::/16, https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

23. 6to4 - Security considerations 1 * if the source IPv6 address is a 6to4 IPv6 address, its corresponding 6to4 router IPv4 address matches the IPv4 source address in the IPv4 encapsulation header, https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

24. 6to4 - Security considerations 1 * similarly, if the destination IPv6 address is a 6to4 IPv6 address, its corresponding 6to4 router IPv4 address matches the IPv4 destination address in the IPv4 encapsulation header, https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

25. 6to4 - Security considerations 1 * any embedded 6to4 router IPv4 address is global unicast. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

26. 6to4 - Websites and lists 1 * [http://www.kfu.com/~nsayer/6to4/ Public 6to4 relay routers]: See [http://web.archive.org/web/200801121941 46/http://www.kfu.com/~nsayer/6to4/ Archive.org cache] https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

27. 6to4 - Websites and lists 1 * [http://bgpmon.net/6to4.php 6to4 relay routers on BGPmon.net]: Lists autonomous systems (ASs) announcing IPv4 Ipv6 6to4 anycast prefixes in time https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

28. 6to4 - Other hosts 1 * Comcast operates 6to4 relays as part of their IPv6 trials. The 6to4 relays were turned up on August 17, 2010. These 6to4 relays are available via the standard 6to4 Anycast IP address which according to RFC 3068 is 192.88.99.1. Devices attempting to use 6to4 within the Comcast network should automatically discover and utilize these 6to4 relays, without end user intervention or configuration. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

29. For More Information, Visit: https://store.theartofservice.co m/itil-2011-foundation- complete-certification-kit- fourth-edition-study-guide- ebook-and-online-course.html https://store.theartofservice.co m/itil-2011-foundation- complete-certification-kit- fourth-edition-study-guide- ebook-and-online-course.html The Art of Service https://store.theartofservice.com