Adding the support for TCP-based DNS datagram exchange is simple. We can use one of the request-processing hooks, called ``process_connection.'' Since it completely overtakes all other request-processing hooks, it allows to implement virtually any TCP-based protocol. The only complication is that the hook function needs to operate on the native Apache abstraction of a TCP connection, which involves some additional APR calls to access the raw content of the stream. A similar situation occurs when translating a raw DNS response to the Apache format. Except for these details, however, there are no substantial problems.