As of 8 p.m. EST on Tuesday, more than 300 organizations, including Google, Facebook, and Yahoo, are testing a new way of routing information around the Internet: Internet Protocol version 6 (IPv6). Though the test run will only last 24 hours, participants may learn valuable lessons about how transitioning to IPv6 could affect their sites and their users.

The Internet has simply outgrown IPv4 — the last few addresses were allotted this past February. IPv4 uses 32-bit addresses, which allow about 4.3 billion unique addresses. IPv6 uses 128-bit addresses, which make possible around 340 trillion trillion trillion unique addresses.