By Robert McMillan
IDG News Service
May 15, 2008
A server problem at the U.S. National Security Agency has knocked the
secretive intelligence agency off the Internet.
The nsa.gov Web site was unresponsive at 7 a.m. Pacific time Thursday
and continued to be unavailable throughout the morning for Internet
The problem was resolved at around 11 a.m. Pacific time, according to
Web site measurement company Netcraft.
The Web site was unreachable because of a problem with the NSA's DNS
(Domain Name System) servers, said Danny McPherson, chief research
officer with Arbor Networks. DNS servers are used to translate things
like the Web addresses typed into machine-readable Internet Protocol
addresses that computers use to find each other on the Internet.
The agency's two authoritative DNS servers were unreachable Thursday
morning, McPherson said.
Because this DNS information is sometimes cached by Internet service
providers, the NSA would still be temporarily reachable by some users,
but unless the problem is fixed, NSA servers will be knocked completely
off-line. That means that e-mail sent to the agency will not be
delivered, and in some cases, e-mail being sent by the NSA would not get
"We are aware of the situation and our techs are working on it," a NSA
spokeswoman said at 9:45 a.m. PT. She declined to identify herself.
A similar DNS problem knocked Youtube.com off-line in early May.
There are three possible reasons the DNS server was knocked off-line,
McPherson said. "It's either an internal routing problem of some sort on
their side or they've messed up some firewall or ACL [access control
list] policy," he said. "Or they've taken their servers off-line because
That "something else" could be a technical glitch or a hacking incident,
In fact, the NSA has made some basic security mistakes with its DNS
servers, according to McPherson. The NSA should have hosted its two
authoritative DNS servers on different machines, so that if a technical
glitch knocked one of the servers off-line, the other would still be
reachable. Compounding problems is the fact that the DNS servers are
hosted on a machine that is also being used as a Web server for the
NSA's National Computer Security Center.
"Say there was some Apache or Windows vulnerability and hackers
controlled that server, they would now own the DNS server for nsa.gov,"
he said. "That really surprised me. I wouldn't think that these guys
would do something like that."
The NSA is responsible for analysis of foreign communications, but it is
also charged with helping protect the U.S. government against cyber
attacks, so the outage is an embarrassment for the agency.
"I am certain that someone's going to send an e-mail at some point
that's not going to get through," McPherson said. "If it's related to
national security and it's not getting through, then as a U.S. citizen,
that concerns me."
(Anders Lotsson with Computer Sweden contributed to this report.)
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