Change in network address for Haskins Lab

RFC 634 announces that the Haskins Laboratory Very Distant Host connection will move between telephone company circuits managed by different network facilities. The host was attached to BBN (the Boston node, IMP #5) and will move to Harvard (IMP #9). The host number—the identifier within that facility—remains 3, but the overall network address changes from 197 to 201 to reflect the new connection point.

The move depends on the local telephone company completing new circuits, so the exact date is uncertain but expected between May 8 and May 22, 1974. Users and network operators will need to update their address tables to route messages to the new location.

In the ARPANET, network addresses are assigned based on the IMP (Interface Message Processor) serving the host and the host position within that IMP. The address 197 identified the Haskins Lab host on IMP #5 (BBN), and address 201 identifies the same host on IMP #9 (Harvard). The host number—position 3—is preserved because it remains the same logical resource; only its attachment point changes.

This scheme requires all network nodes to maintain current address tables so that routing decisions correctly locate hosts when they move between IMP connections. The RFC is thus not only an announcement but also an operational requirement: administrators must update their network configuration.

RFC 634 is an infrastructure notice from the earliest days of ARPANET. It documents the administrative process for managing host migrations on the network. The specific address change announced is historical and has no modern relevance, but the RFC demonstrates how early networks required explicit coordination and communication about topology changes.