Managing use of intermediate destination computing nodes for provided computer networks

A computer-implemented method, comprising:

• providing, by one or more computing systems of a configurable network service and for a client of the configurable network service, a virtual computer network having multiple computing nodes based on configuration information received from the client, the providing including overlaying the virtual computer network on a substrate network of the configurable network service;
• forwarding, by the one or more computing systems and based on the configuration information, communications over the substrate network between the multiple computing nodes;
• updating, by the one or more computing systems and while the virtual computer network is in use, the configuration information based on instructions from the client to add functionality for an intermediate computing node in the virtual computer network;
• and
• providing, by the one or more computing systems, the added functionality of the intermediate computing node for an additional communication without modifying any other computing nodes in the virtual computer network, including forwarding, by the one or more computing systems and based on the updated configuration information, the additional communication over the substrate network to the intermediate computing node to obtain the added functionality for the additional communication.

A system, comprising:

• one or more hardware processors of one or more computer systems;
• and
• one or more memories with stored instructions that, when executed by at least one of the one or more hardware processors, cause the system to:
• instantiate, for a client of a configurable network service, a virtual computer network having multiple computing nodes based on configuration information received from the client, wherein the configuration information indicates a network topology for the virtual computer network, and wherein the instantiating includes overlaying the virtual computer network on a substrate network;
• update, while the virtual computer network is in use, the configuration information based on instructions from the client;
• add, based on the instructions from the client, functionality for an indicated computing node in the virtual computer network without modifying any other computing nodes in the virtual computer network, including to modify the network topology of the virtual computer network while the virtual computer network is in use to locate the indicated computing node in the modified network topology between two or more groups of the multiple computing nodes;
• determine, based on the updated configuration information, to use the indicated computing node with an additional communication;
• and
• forward the additional communication over the substrate network to the indicated computing node to obtain the added functionality for the additional communication.