By Drew FitzGerald
Network engineers are buzzing this week as the Internet outgrows
some of its gear.
Internet providers, corporations and universities all rely on a
common map of routes to send emails, videos and everything else on
the Web where it's supposed to go.
That Internet atlas has thickened, and some of the machines that
read it are now straining to hold all the pages.
While a precise count is elusive, many technicians are reporting
that the total number of world-wide Internet routes is near or
already past half a million, usually abbreviated 512K. Older
network routers from Cisco Systems Inc. and other makers can't hold
any more unless they are tweaked.
The fix is simple. Engineers can buy new gear or raise their
routers' memory caps and reboot. But some Web companies need to
reconfigure each device one at a time, and the fallout is hard to
judge given the numbers involved. The work already caused some
websites to go offline Tuesday. More links could suffer in the days
ahead.
The situation echoes--if faintly--the hubbub over the feared Y2K
computer glitch in the late 1990s, when experts warned that systems
could fail because their dating functions hadn't been designed to
handle the turn of the century.
This time, Internet specialists are being careful to warn
against a descent into that era's hyperbole and shrill warnings of
disasters that never materialized.
Still, the issue was adding to many engineers' real-life
workload as recently as this week. Website hosting service Liquid
Web Inc. said that some users had trouble connecting to a portion
of its customers' Web pages Tuesday until its technicians sorted
out the problem.
"It's certainly an issue that pushed some of our routers over
the limit, " Liquid Web spokesman Cale Sauter said. "Getting to the
bottom of everything took a large portion of the business day."
The Internet rests on two important directories: the Domain Name
System, which tells packets of information where they should be
going, and the global routing table, which tells them how to get
there. When either system breaks down, some Internet addresses can
get cut off from the rest of the Web.
Network engineers have been discussing the routing problem for
years through mailing lists and highly technical conferences with
names like the North American Network Operators' Group. Internet
traffic handlers like Level 3 Communications Inc. said they bought
new equipment with extra memory more than a year ago, heading off
the problem before it affected users.
The problem also draws attention to a real, if arcane, issue
with the Internet's plumbing: the shrinking number of addresses
available under the most popular routing system. That system,
called IPv4, can handle only a few billion addresses. But there are
already nearly 13 billion devices hooked up to the Internet, and
the number is quickly growing, Cisco said.
Version 6, or IPv6, can hold many orders of magnitude more
addresses but has been slow to catch on. In the meantime, network
engineers are using stopgap measures
More websites and broadband firms are likely to feel the pinch
in coming days as they hit the seemingly arbitrary limit, said Jim
Cowie, chief scientist at network management company Dyn. Web
companies usually have slightly different versions of the digital
map, so their databases will breach the 512K route mark at
different times.
Newer routers can handle more than one million Internet routes,
but experts say that number also could prove too low in the long
run given the Web's fast growth rates.
Write to Drew FitzGerald at andrew.fitzgerald@wsj.com
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