Cooperative proxy auto-discovery and connection interception
In a network supporting transactions between clients and servers and proxies that are interposable in a network path, a pair of proxies can modify a packet stream such that packet data from client to server is transformed at a client-side proxy of the pair and untransformed at a server-side of the pair and packet data from server to client is transformed at the server-side proxy and untransformed at the client-side proxy. A discovering proxy transparently discovers its position in a proxy pair by using proxy signals. A discovering proxy might determine that it is a client-side proxy by receipt of a packet from client without a proxy signal, or that it is a server-side proxy by receipt of a packet from server without a return proxy signal. Once a proxy pair is discovered, it might transform traffic from server to client or vice versa, transforming and untransforming the traffic.
1. In a network supporting transactions and having network nodes from which transactions are requested or from which responses are issued responsive to transaction requests, a method of probing for node devices on a network path comprising:
receiving, at a first probe node in the network path, a first packet from a target client wherein the first packet is a packet directed at a target server;
modifying the first packet to signal presence of the first probe node in the network path, thus forming a modified first packet having therein a presence signal;
forwarding the modified first packet onto the network path, directed toward the target server;
monitoring, at the first probe node, packets directed at the target client and apparently from the target server to detect packets containing return signals, wherein a return signal is a signal from a device at a second probe node that detects the presence signal in the modified first packet and wherein the return signal is an indication that the device at the second probe node detected the presence signal as being a probing signal;
acting on a successful probe if a responsive return signal is received corresponding to a presence signal sent from the first probe, wherein the mapping table is shared in storage accessible to the first probe node;
updating a mapping table with results of a successful probe; and
following a current connection, using the updated mapping from the mapping table in a later connection.