An affinity-based router and method for routing and load balancing in an encapsulated cluster of server nodes is disclosed. The system consists of a multi-node server, wherein any of the server nodes can handle a client request, but wherein clients have affinity to one or more of the server nodes that are preferred to handle a client request. Such affinity is due to state at the servers either due to previous routing requests, or data affinity at the server. At the multi-node server, a node may be designated as a TCP router. The address of the TCP router is given out to clients, and client requests are sent thereto. The TCP router selects one of the nodes in the multi-node server to process the client request, and routes the request to this server; in addition, the TCP router maintains affinity tables, containing affinity records, indicating which node a client was routed to. In processing the client request, the server nodes may determine that another node is better suited to handle the client request, and may reset the corresponding TCP router affinity table entry. The server nodes may also create, modify or delete affinity records in the TCP router affinity table. Subsequent requests from this client are routed to server nodes based on any affinity records, possibly combined on other information (such as load).