At least one intelligent network interface card (INIC) is coupled to a host computer to offload protocol processing for multiple network connections, reducing the protocol processing of the host. Plural network connections can maintain, via plural INIC ports and a port aggregation switch, an aggregate connection with a network node, increasing bandwidth and reliability for that aggregate connection. Mechanisms are provided for managing this aggregate connection, including determining which port to employ for each individual network connection, and migrating control of an individual network connection from a first INIC to a second INIC.