Ipv4 and Ipv6

IPv4 and IPv6 have several differences and similarities. One of the similarities is they both use DNS. DNS is an important part of communicating data on the internet or on a private network. DNS takes human readable names and translates them into IP addresses that are then used to send packets of information for an application on one computer to an application on another computer on the internet or on a private network. DNS is important because most people cannot remember long IP addresses, but they can remember names easily. DNS use in IPv6 is different than DNS use inIPv4; there are many things that have remained the same and some things that are different. It is important to learn about these similarities and differences in the way IPv6 and IPv4 use DNS to properly set-up a network that can facilitate the use of one or both of these IP addressing versions. This will be important because in the near future IPv4 will be replaced with IPv6, until then many networks will use both IP versions this is called a dual stack. Unit1 Project 1
The differences between the implementation of DNS in IPv6 and IPv4 Many differences exist between DNS in IPv6 and IPv4. First, automatic updates of DNS records are supported in IPv6. Automatic updates are not supported in IPv4. IPv4 records must be updated by manually updating them or dynamically updating them. In networks where the host gets their IP address by using Dynamic Host Configuration Protocol (DHCP) and the host may change locations frequently, dynamic updating is the best way to update resource records.
DHCP works by allowing devices that do not have an IP address already assigned to them to lease an IP address for a specified amount of time in which that device becomes part of that IP network. This is important in any company or organization that has employees that work from laptops, tablets, or a variety of other wireless devices. Second, IPv4 and IPv6 do not use the same host records. IPv4 uses “A” records and IPv6 uses “AAAA” (quad resource records) (Configuring DNS for IPV6/IPV4 Coexistence, 2003). The use of both of these file types in the DNS servers within the DNS hierarchy can become complex, but it will be necessary until the complete changeover from IPv4 to IPv6 has taken place. Type “A” records will become obsolete once the changeover to IPv6 has taken place and once again the DNS servers within the DNS hierarchy will become less complex with only one file type to support. It is called a dual stack when the DNS servers within the DNS hierarchy are able to handle both IPv4 and IPv6 file types. This technology of dual stacking a system has come along way from its conceptions. It now includes features such as DSTM (Dual Stack Transition Mechanism). DSTM works similar to DHCP in that it issues a temporary IP address to a device, and it is used in networks were the number of IPv4 addresses available are limited (Schorr, 2004). Another process for handling an IPv6 address on an IPv4 network is called tunneling. There are many ways that this process can be configured. The configuration itself is dependent on who the sender is and who the intended receiver is in the communication. Specifically, the tunneling can take place between two routers, two hosts, or a host to a router. Last, Pointer (PTR) records can be created to assist in the resolution of an IPv6 address. This is necessary because of the substantial differences in the length of IPv6 addresses versus IPv4 addresses. PTR records are files in the resources records that store IPv6 addresses to assist in the resolution of domain names to IPv6 addresses. The creation of these files is optional, but their configuration is recommended.
The similarities between the implementations of DNS in IPv4 and IPv6 IPv4 and IPv6 share many things in common. First, IPv4 and IPv6 use the same domain names when resolving domain names to IP addresses. The domain names do not change in the implementation of IPv6 just the IP addresses. DNS works by taking a domain name and then it checks its resource records whether they be type “A” or “AAAA”, depending on the IP version used, to see if this domain name is listed. If the domain name is listed in these “A” or “AAAA” records, the name is resolved. If the domain name is not in the “A” or “AAAA” records held locally, the DNS servers queries the root DNS server to resolve the domain name. This type of query is referred to as a reclusive query; an iterative query is the type where the domain name is expected to be resolved at the local DNS level (How DNS Works, 2003). It is plain to see how IPv4 and IPv6 use the same procedure for resolving domain names. Second, IPv4 and IPv6 use the same DNS servers. Many companies and organizations have not made a complete change over from IPv4 to IPv6, so the fact that they both use the same servers is important. It also saves the company or organization money because many of them house their own local DNS servers. This is especially true in large organizations. Third, it is possible for a DNS query to return a result of one IPv4 address and one or many IPv6 addresses. This is because it is possible for a device to have more than one IPv6 address assign to it. The devices that reside at the source and destination addresses decide on using one of two procedures to decide on the source or destination’s address. These procedures provide network administrators with options to override default behaviors. In dual stack networks, the destination device considers both IP versions and assigns one of them as the preferred IP addressing scheme used. Disadvantages of using IPv6 DNS as compared to IPv4 DNS There are disadvantage associated with the implementation of DNS in IPv6. The first, disadvantage of using IPv6 is it could possibly make your access to the web slower. The reason for this is that many of today’s networks run a dual stack network in serial and not in parallel (IPV6 Will Slow You Down (DNS), 2011). This is an issue that many are already addressing by the owners of many of today’s manufactures of operating systems. Second, IPv6 is not backwards compatible with IPv4. There are many ways to solve this problem. A dual stack can be run on the network or IPv6 packets can be encapsulated in an IPv4 packet (also known as tunneling) (Schorr, 2004). These solutions are not perfect; there is no easy solution. All these solutions can be complex to implement on an IP network. Third, many older networking devices and servers do not support IPv6 functionality. The complete change over to IPv6 would require any company, organization, or individual with legacy networking equipment and servers to upgrade to networking devices and servers that are IPv6 compatible. This will cost a substantial amount of money for a large company or organization that may have many servers and networking devices residing in there network.
Advantages of using IPv6 DNS as compared to IPv4 DNS The first advantage of using IPv6 over IPv4 is that both IP versions resolve domain names into IP addresses using the same procedure. This is something that any IT technician or network administrator will appreciate, because it will make their jobs easier. The Second advantage of using IPv6 over IPv4 is that IPv6 automatically updates its records is a great advantage over IPv4. In IPv4 implementations, the network administrator or IT technician would have to manually update records or set up dynamic update on the network. Both of these approaches take extra time when setting up a network.
Conclusion
It is important to know the differences between the use of DNS in IPv4 and IPv6. Some of these differences will be of an advantage to the network administrator or IT technician, and other differences will be of a disadvantage to the network administrator or IT technician. The proper implementation of either DNS in IPv4 or IPv6 will require that a networking professional research and understand the differences an similarities and the advantages and disadvantages to using DNS in both IP versions. After they understand these issues, networking professionals will be able to install dual stacked networks or IPv6 on any given network without any problems. It is important that these professionals take the time to understand how the implementation of IPv6 can make their jobs easier.

References
Configuring DNS for IPV6/IPV4 Coexistence. (2003, March 28). Retrieved September 7, 2012, from microsoft.com: http://technet.microsoft.com/en-us/library/cc738372(v=ws.10).aspx
How DNS Works. (2003, March 28). Retrieved September 7, 2012, from microsoft.com/en-us: http://technet.microsoft.com/en-us/library/cc772774(WS.10).aspx
IPV6 Will Slow You Down (DNS). (2011, May 18). Retrieved September 7, 2012, from belshe.com/: http://www.belshe.com/2011/05/18/ipv6-will-slow-you-down-dns/
Schorr, M. (2004, January 5). IPV4 and IPV6: A Comparison. Retrieved September 7, 2012, from myitforum.com: http://www.myitforum.com/articles/1/view.asp?id=6720

References: Configuring DNS for IPV6/IPV4 Coexistence. (2003, March 28). Retrieved September 7, 2012, from microsoft.com: http://technet.microsoft.com/en-us/library/cc738372(v=ws.10).aspx How DNS Works. (2003, March 28). Retrieved September 7, 2012, from microsoft.com/en-us: http://technet.microsoft.com/en-us/library/cc772774(WS.10).aspx IPV6 Will Slow You Down (DNS). (2011, May 18). Retrieved September 7, 2012, from belshe.com/: http://www.belshe.com/2011/05/18/ipv6-will-slow-you-down-dns/ Schorr, M. (2004, January 5). IPV4 and IPV6: A Comparison. Retrieved September 7, 2012, from myitforum.com: http://www.myitforum.com/articles/1/view.asp?id=6720