BEIJING, Jan. 22 (Xinhua) -- Internet experts in China called for intensified efforts to safeguard the country's domain name system (DNS) after it malfunctioned on Tuesday, leaving users unable to access many websites.
DNS translates easily-remembered domain names to numerical IP addresses, which can be recognized and processed through the Internet.
On Tuesday, a number of Chinese netizens intermittently lost access to websites with the domain name ".com," including the country's major news portal Sina.com and Baidu.com, the most popular search engine, according to media reports.
The China Internet Network Information Center (CNNIC) said through its account at SinaWeibo, a Twitter-like service in China, that the access failure that affected many users in the country was caused by a problem with top-level domain name root servers.
Despite the malfunction, ".cn," the national top-level domain name, remains unaffected, said the CNNIC on Wednesday.
"We have tracked and analyzed the DNS and found that at least two of the 13 root name servers around the world were affected," said Dong Fang, Internet Engineer with 360 Security Solution.
He said that it was likely a man-made event, either hacker attacks or DNS hijacking.
Security problems are not rare in China, as the ".cn" domain, which is administered and run by the CNNIC, suffered massive attacks in August 2013, resulting in short-term website failures.
Experts said that security awareness about DNS is weak in China and most major domain name servers are poorly guarded.
"All the root name servers are located in the United States, Japan and European countries. A problem with them would affect all the domain name processes and website visits in China," Dong Fang said.
Li Xiaodong, executive director of the CNNIC, called on the central government to spend more on the country's DNS infrastructure and stressed that a quick-responding mechanism for emergencies is badly needed.
"We need to establish a monitoring system over DNS and response system for accidents," Dong Fang added. "Building root domain name servers in China should be completed as soon as possible."
In December 2013, more than 2.22 million Internet terminals in China were infected with viruses, while vandalism occurred on 6,823 websites and 6,171 sites were infected with "backdoors," data from the National Computer Network Emergency Response Technical Team showed.