A computer-implemented method for facilitating dynamic migration of networked computing nodes, the method comprising: under control of one or more computing devices configured to dynamically migrate a first computer network (130; 190) having multiple computing nodes (134; 191) at a first geographical location to a remote virtual second computer network (120; 120a) at a second geographical location while the first computer network is in use, and for each of at least some of the multiple computing nodes of the first computer network: receiving an indication of a migration of the computing node of the first computer network to a distinct replacement computing node (124; 165, 166, 184) at the second geographical location that is part of the remote virtual computer network, wherein the migrated computing node uses a network address of the first computer network before the migration and after the migration, the replacement computing node of the remote virtual computer network replaces the migrated computing node as part of the first computer network and uses said network address of the first computer network that was used by the migrated computing node before the migration; automatically associating the network address used by the replacement computing node with a gateway device (132; 192) on the first computer network that is configured to represent the replacement computing node of the remote virtual computer network; and after the automatic associating of the network address, automatically managing one or more additional communications sent over the first computer network to the network address used by the replacement computing node, the managing of each of the additional communications including, after the additional communication is forwarded over the first computer network to the gateway device that represents the replacement computing node, forwarding the additional communication to the remote virtual computer network for delivery to the replacement computing node. under control of one or more computing devices configured to dynamically migrate a first computer network (130; 190) having multiple computing nodes (134; 191) at a first geographical location to a remote virtual second computer network (120; 120a) at a second geographical location while the first computer network is in use, and for each of at least some of the multiple computing nodes of the first computer network: receiving an indication of a migration of the computing node of the first computer network to a distinct replacement computing node (124; 165, 166, 184) at the second geographical location that is part of the remote virtual computer network, wherein the migrated computing node uses a network address of the first computer network before the migration and after the migration, the replacement computing node of the remote virtual computer network replaces the migrated computing node as part of the first computer network and uses said network address of the first computer network that was used by the migrated computing node before the migration; automatically associating the network address used by the replacement computing node with a gateway device (132; 192) on the first computer network that is configured to represent the replacement computing node of the remote virtual computer network; and after the automatic associating of the network address, automatically managing one or more additional communications sent over the first computer network to the network address used by the replacement computing node, the managing of each of the additional communications including, after the additional communication is forwarded over the first computer network to the gateway device that represents the replacement computing node, forwarding the additional communication to the remote virtual computer network for delivery to the replacement computing node. receiving an indication of a migration of the computing node of the first computer network to a distinct replacement computing node (124; 165, 166, 184) at the second geographical location that is part of the remote virtual computer network, wherein the migrated computing node uses a network address of the first computer network before the migration and after the migration, the replacement computing node of the remote virtual computer network replaces the migrated computing node as part of the first computer network and uses said network address of the first computer network that was used by the migrated computing node before the migration; automatically associating the network address used by the replacement computing node with a gateway device (132; 192) on the first computer network that is configured to represent the replacement computing node of the remote virtual computer network; and after the automatic associating of the network address, automatically managing one or more additional communications sent over the first computer network to the network address used by the replacement computing node, the managing of each of the additional communications including, after the additional communication is forwarded over the first computer network to the gateway device that represents the replacement computing node, forwarding the additional communication to the remote virtual computer network for delivery to the replacement computing node.