Root Zone

Root Zone refers to the highest level of the Domain Name System (DNS) structure. It contains the names and the numeric IP addresses for all the top level domain names such as the gTLDs .com, .net, .org, .jobs, all the country code top level domains (ccTLDs) for example .us, .uk .ph including the entire list of all the root servers.

According to the 2009 report of the Root Scaling Study Team, the DNS root zone is small which contains only 280 delegations of generic, country code and internationalized top level domain names (TLDs and its size is more or less 80,000 bytes. It also changes slowly and absorbs only one minor change per TLD every year.

Root Zone Management Process

The National Telecommunications Information Administration (NTIA), ICANN, Verisign and the Root Server Operators play significant functions in the management process of root zone.

NTIA an agency under the United States Department of Commerce represents the Federal government in a contract entered with ICANN and Verisign which grants the organizations separate functions in managing the performance of the root zone. NTIA is responsible in reviewing and approving whatever changes that needs to be implemented within the root zone.

ICANN is the operator of the Internet Assigned Numbers Authority IANA which is responsible in the day to day management of DNS root zone. IANA assigns the operators of the top level domain and ensures the maintenance and the administrative details of the TLDs. It is also responsible in the coordination of the Internet Protocol (IP) and Autonomous System (AS) numbers to the Regional Internet Registries (RIR).

Verisign formerly Network Solutions, Inc. serves as root zone administrator under a cooperative agreement entered with the United States government since 1998.

The Root Server Operators' primary role is to make sure that the operations of root zone is always accurate, available, reliable and secure.There are thirteen Root Server Operator in the data base of the root zone which include:

• A - VeriSign Global Registry Services
• B - Information Sciences Institute
• C - Cogent Communications
• D - University of Maryland
• E - NASA Ames Research Center
• F - Internet Systems Consortium, Inc.
• G - U.S. DOD Network Information Center
• H - U.S. Army Research Lab
• I - Autonomica/NORDUnet
• J - VeriSign Global Registry Services
• K - RIPE NCC
• L - ICANN
• M - WIDE Project

Root Zone Operational Changes

On February 3, 2009, the ICANN Board enumerated the upcoming operational changes that will be implemented in the DNS root zone such as the addition of IPv6 records to the root, new generic top level domains (gTLDs), new country code Internationalized Domain Names (cc IDNs), IDNs, and the implementation of DNSSEC. In connection to the anticipated root zone operational changes, the Board requested Security and Stability Advisory Committee (SSAC) and Root Server System Advisory Committee (RSSAC) to hold a joint study to analyze its impact to the stability and security to the DNS root server system. Furthermore, the Board reques ed both the committees to identify the capacity and scaling of the root server system to be able to solve any technical and operational challenges that might take place when the proposed changes are implemented. Some ICANN senior technical staff will also take part in the study.

Root Scaling Study Report

The SSAC, RSSAC and ICANN Staff responded to the request of the ICANN Board by creating a Scaling Steering Group to conduct the study. On September 7, 2009, a report entitled: Report on the Impact on the DNS Root System of Increasing the Size and Volatility of the Root Zone was submitted by the Root Scaling Study Team for the Scaling Steering Group with the following findings and recommendations:

• Any of the proposed changes has an effect to the growth of the root zone. The study team suggested that it is best to add or make changes to the root zone with a large or sudden impact. Gradual changes can be added at later stages.
• Additional new TLDs will increase both the number of entries and the size of the root zone however an increase in the number of TLDs will not increase the number of request per year per TLD.
• Adding DNSSEC changes the nature of the root zone wherein it will no longer be an atomic unit or an individual resource record instead a group of resource record.Implementation of the DNSSEC will result to a much bigger amount of data carried in the zone as well as larger zone transfers.Signature and other security related data will will added to queries to the DNS will needs more bandwidth network resources and the signature data's needs to be regularly updated because they have expiration dates to avoid serving bad data and to avoid replay attacks.
• Additional IDN results to changes in the root zone similar to adding a TLD.
• Adding IPv6 records to the root zone will add glue records for the name server of every TLD. This means that the amount of data increases per TLD in the root zone and the number of changes per TLD will also increase each year.

The Root Scaling Study Team also found that the proposed changes to the root also affects the end-system applications of the internet such as the web browsers, intermediary “middleboxes” that perform traffic shaping, firewall, and caching functions; and ISPs that manage the DNS services provided to internet users.

In addition the team also recommended further study on how to detect the important signs of stress or problems in every root zone mangement function and how to arrange communication between the individuals primary involved in the root zone management system to ensure a timely intelligence support and an effective cooperative action is available and can be taken anytime to resolve the effects of discontinuities before causing further problems.