Eibd provides over a TCP/IP and/or unix domain sockets access to the EIB/KNX-bus using a simple
protocol. It provides access at layer 4 as well as to high level mangement function. Multiple
concurrent users are supported. A special bus monitor mode call vBusmonitor is implemented, which
delivers all traffic, which eibd passes, but not disturbs send activities.

Additionally, eibd can act as limited EIBnet/IP Tunneling and/or Routing Server. The limitation is,
that only one KNX address can be used as source address of EIBnet/IP Clients. This address is shared
between multiple possible routing or tunneling connections. To the EIBnet/IP client, the address
0.0.0 is used, to the EIB/KNX bus the address of the interface device is used. eibd maps between
these addresses (like NAT for TCP/IP).

Enabling the EIBnet/IP Server disables the normal bus monitor function (vBusmonitor still works). It
supports all interfaces supported by eibd. In an experiment, the ETS read successfully the device
infos over EIBnet/IP Tunneling to a chain of some eibds connected through EIBnet/IP Tunneling and a
TPUART at the last. 

https://www.auto.tuwien.ac.at/~mkoegler/index.php/eibd