The Internet engineering community will be eating its own dog food tonight. For one hour, the 1,250 network experts at the Internet Engineering Task Force meeting will be able to access the Internet only through IPv6. The IETF created IPv6 in the mid-1990s, but this upgrade to the Internet's main communications protocol has not yet been widely deployed -- even by the technology's biggest proponents here. Network World National Correspondent Carolyn Duffy Marsan talked with IETF Chair Russ Housley about the group's IPv6 experiment, why the transition to IPv6 is taking so long, and whether the IETF leadership is starting to panic about IPv4 addresses running out. Here are excerpts from their conversation: