Uh-Oh: Internet Has 340 Undecillion Addresses New IP address system should cover us By Neal Colgrass, Newser Staff Posted Jun 9, 2012 5:22 PM CDT 13 comments Comments One of 340 trillion trillion trillion Web addresses, when it gets written. (Shutterstock) (Newser) – Looks like the Internet has grown a tad—from about 4.3 billion unique addresses to 340 trillion trillion trillion of them, or 340 undecillion. What's the big deal? Well, that growth rate will soon eat up every available IP address, so Internet honchos have devised a new system to designate them—like when we added digits to telephone numbers in the 1990s to accommodate the growing US phone system, CNN Money reports. The new IP address system, called IPv6, will replace IPv4 gradually and co-exist for some time (like digital and analog TV did). The difference: While IPv4 looks like xxx.xxx.xxx.xxx, with each "xxx" going from 0 to 255, IP v6 has eight quadruple-x's separated by colons, with each x ranging from 0 to 9 or a to f. And with most major networks and websites already participating, you likely won't feel a thing.