Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

SD Supercomputer Center researchers find unnecessary traffic saturating a key Internet ’root’ server

24.01.2003


Scientists at the San Diego Supercomputer Center (SDSC) at UCSD analyzing traffic to one of the 13 Domain Name System (DNS) “root” servers at the heart of the Internet found that the server spends the majority of its time dealing with unnecessary queries. DNS root servers provide a critical link between users and the Internet’s routing infrastructure by mapping text host names to numeric Internet Protocol (IP) addresses. Researchers at the Cooperative Association for Internet Data Analysis (CAIDA) at SDSC conducted a detailed analysis of 152 million messages received on Oct. 4, 2002, by a root server in California, and discovered that 98 percent of the queries it received during 24 hours were unnecessary. The researchers believe that the other 12 DNS root servers likely receive similarly large amounts of bad requests.


Locations of the Internet’s 13 Domain Name System “root” servers.
Credit: SDSC/CAIDA



Some experts regard the system of 13 DNS root servers, the focus of several studies by CAIDA researchers, as a potential weak link in the global Internet. Spikes in DNS query traffic caused by distributed denial-of-service attacks are routinely handled by root server operators. Occasionally, as on Oct. 21, 2002, all 13 root servers are attacked simultaneously. Although no serious damage resulted from that incident, Richard A. Clarke, chairman of the President’s Critical Infrastructure Protection Board and special advisor to the president for cybersecurity, has expressed concern that attacks against root servers could potentially disrupt the entire Internet. CAIDA researchers will discuss their analysis of the root server and other cybersecurity findings with Clarke during his visit to SDSC on Jan. 28. CAIDA researchers will also present a paper detailing some of their DNS analysis at the 2003 Passive and Active Measurement Workshop April 6–8 at UCSD.

Only about 2 percent of the 152 million queries received by the root server in California on Oct. 4 were legitimate, while 98 percent were classified as unnecessary. CAIDA researchers are seeking to understand why any root server would receive such an enormous number of broken queries daily from lower level servers. “If the system were functioning properly, it seems that a single source should need to send no more than 1,000 or so queries to a root name server in a 24-hour period,” said CAIDA researcher Duane Wessels. “Yet we see millions of broken queries from certain sources.”


Wessels categorized all the queries received by the California root server on Oct. 4, 2002, into nine types. About 70 percent of all the queries were either identical, or repeat requests for addresses within the same domain. It is as if a telephone user were dialing directory assistance to get the phone numbers of certain businesses, and repeating the directory-assistance calls again and again. Lower level servers and Internet service providers (ISPs) could save—or cache—these responses from root servers, improving overall Domain Name Service performance.

About 12 percent of the queries received by the root server on Oct. 4, were for nonexistent top-level domains, such as “.elvis”, “.corp”, and “.localhost”. Registered top-level domains include country codes such as “.au” for Australia, “.jp” for Japan, or “.us” for the United States, as well as generic domains such as “.com”, “.net”, and “.edu”. In addition, 7 percent of all the queries already contained an IP address instead of a host name, which made the job of mapping it to an IP address irrelevant.

Researchers believe that many bad requests occur because organizations have misconfigured packet filters and firewalls, security mechanisms intended to restrict certain types of network traffic. When packet filters and firewalls allow outgoing DNS queries, but block the resulting incoming responses, software on the inside of the firewall can make the same DNS queries over and over, waiting for responses that can’t get through. Name server operators can use new tools such as dnstop, a software program written by Wessels and available at http://www.caida.org/tools/utilities/dnstop/ to detect and warn of these and other misconfigurations, significantly reducing bad requests.

Name-service errors in software implementations were reported as early as 1992, but some of these bugs are still with us today. Explosive Internet growth during the last decade exacerbates problems caused by defective name servers.

Rex Graham | EurekAlert!
Further information:
http://www.caida.org/projects/dns-analysis/
http://www.caida.org/tools/utilities/dnstop/
http://ucsdnews.ucsd.edu/newsrel/science/sdscRoot.htm

More articles from Information Technology:

nachricht The Flexible Grid Involves its Users
27.09.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Optical fiber transmits one terabit per second – Novel modulation approach
16.09.2016 | Technische Universität München

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

 
Latest News

New Multiferroic Materials from Building Blocks

29.09.2016 | Materials Sciences

Silicon Fluorescent Material Developed Enabling Observations under a Bright “Biological Optical Window”

29.09.2016 | Materials Sciences

X-shape Bio-inspired Structures

29.09.2016 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>