portfwd, port forwarding daemon, stands for port forwarding daemon. it's a small c++ utility which forwards incoming tcp connections and/or udp packets to remote hosts.
features
forwarding of tcp segments.
forwarding of udp datagrams.
forwarding of ftp in active and/or passive modes.
transparent proxying available under linux. portfwd detects such facility in "./configure" time by searching the definition of msg_proxy in .
dns names for destination hosts can be resolved upon startup or on demand (see "onthefly" dns option).
portfwd can listen on specific local addresses.
source addresses for outgoing connections can be explicitly specified or automatically selected by the system.
structured configuration language allows specification of multiple simultaneous forwarding processes.
portfwd spawns one forwarder process for each set of ports which are subject to the same rules. within a process, portfwd uses a select()based eventloop to concurrently handle several network events. there is no threading. there is no further process creation after the startup of the configured daemons.
the destination of a connection/datagram can be selected based on its source address/port pair.
portfwd allows simple roundrobin loadbalancing through specification of multiple destinations.
