Internet traffic is growing rapidly and aging hardware platforms used in keeping the global network humming are struggling under the load.
At 4 a.m. Eastern time Aug. 13, Internet users on different mailing lists, forums and Twitter reported sluggish Internet connectivity and intermediate outages worldwide.
Experts later determined that the problem, which affected small portions of the Internet, was related to equipment handling a critical function called Border Gate Protocol (BGP) routing.
"The problem is the Internet keeps growing, and because it keeps growing, more and more routers are going to encounter that unpleasant truth that the Internet now is too big to fit in memory," said Jim Cowie, chief scientist of Dyn.
Cowie founded Internet monitoring company Renesys, which was acquired by Dyn in May.
Collectively, BGP routers, which are typically run by Internet Service Providers (ISPs), create the map of the Internet that a server uses in figuring out where to send traffic so it reaches its destination.
The map, called a routing table, has hundreds of thousands of routes to all the sites that are online. Because what's available changes constantly, BGP routers talk to each other continuously to keep the map up to date.
Talk to ISPs about the size of their routers and their preparations for Internet growth. Discuss router provisioning with IT staff if your enterprise connects directly to the Internet.
The table is stored in a router's very fast memory called ternary content-addressable memory, or TCAM. The recent slowdown occurred when the number of traffic routes topped 512,000, which exceeded the memory capacity of some BGP routers.
That maximum number had not been reached before. Now it is expected to become the new normal over the next several weeks.
To avoid service interruptions, companies should contact their service providers and ask about the size of their routers and their preparations for Internet growth.
Executives in companies that connect directly to the Internet and have their own routers should talk to IT staff responsible for the equipment.
"It's something to be careful about, something to keep an eye on for sure, but definitely nothing to panic about today," Cowie said.
Experts: Internet slowdowns could become more frequent.
Aging routers will have to be replaced in order to supply maps to the growing number of servers connected to devices ranging from computers and mobile phones to cars and smart appliances.
As BGP routers get overtaxed, small numbers of Internet users will experience service interruptions from time to time, Cowie said. The problems will disappear once the router is replaced, upgraded or the memory reallocated to free up space.
"It's not an apocalyptic scenario at all," Cowie sad. "The worst case scenario here is very localized."
In general, large ISPs are prepared for the increase in Internet usage. Smaller ISPs and large enterprises that connect directly to the Internet are more likely to be taken by surprise and go offline briefly.
"People may not have thought about the fact that their limit was getting close, so unfortunately this becomes the wake-up call," Cowie said.