diff --git a/contrib/docker/build.sh b/contrib/docker/build.sh
index adf33c44..2d55f632 100755
--- a/contrib/docker/build.sh
+++ b/contrib/docker/build.sh
@@ -1,15 +1,27 @@
 #!/bin/sh
+stamp=`docker inspect -f '{{.Created}}' ebusd-buildenv 2>/dev/null`
+if [ -z "$stamp" ] || ( rm -f .stamp && touch -d "$stamp" .stamp && [ buildenv/Dockerfile -nt .stamp ] ) ; then
+  echo "updating ebusd build environment..."
+  docker rmi -f ebusd-buildenv 2>/dev/null
+  (cd buildenv && docker build -t ebusd-buildenv .) || exit 1
+fi
 set -e
-(cd buildenv && docker build -t ebusd-buildenv .)
+echo "creating debian image..."
 docker run --rm -it -v `pwd`/../..:/build ebusd-buildenv ./make_debian.sh
 export EBUSD_VERSION=`cat ../../VERSION`
 export EBUSD_ARCH=`docker version|grep -i "Arch[^:]*server"|head -n 1|sed -e 's#^.*/##'`
-cp -a ../../ebusd-${EBUSD_VERSION}_${EBUSD_ARCH}.deb runtime/
+mv ../../ebusd-${EBUSD_VERSION}_${EBUSD_ARCH}_mqtt1.deb runtime/
+echo "building docker image..."
 (cd runtime && docker build -t ebusd .)
-echo "docker image created."
-echo
-echo "to run it interactively on serial device /dev/ttyUSB1:"
-echo "docker run --rm -it --device=/dev/ttyUSB1:/dev/ttyUSB0 -p 127.0.0.1:8888:8888 ebusd"
-echo
-echo "to start it in background on serial device /dev/ttyUSB1:"
-echo "docker run device=/dev/ttyUSB1:/dev/ttyUSB0 -p 127.0.0.1:8888:8888 ebusd"
+cat <<EOF
+docker image created.
+
+to run it interactively on serial device /dev/ttyUSB1:
+docker run --rm -it --device=/dev/ttyUSB1:/dev/ttyUSB0 -p 127.0.0.1:8888:8888 ebusd
+
+to start it in background on serial device /dev/ttyUSB1:
+docker run device=/dev/ttyUSB1:/dev/ttyUSB0 -p 127.0.0.1:8888:8888 ebusd
+
+when using a network device, the "--device" argument to docker can be omitted:
+docker run --rm -it -p 127.0.0.1:8888:8888 ebusd -f --scanconfig -d udp:192.168.178.123:10000 --latency=80000
+EOF
diff --git a/contrib/docker/buildenv/Dockerfile b/contrib/docker/buildenv/Dockerfile
index 2f441ac2..0e871562 100644
--- a/contrib/docker/buildenv/Dockerfile
+++ b/contrib/docker/buildenv/Dockerfile
@@ -1,6 +1,8 @@
 FROM debian
+
 RUN apt-get update
 RUN apt-get install -y git autoconf automake g++ make
+RUN apt-get install -y libmosquitto-dev
 
 WORKDIR /build
-CMD ["/bin/bash"]
\ No newline at end of file
+CMD ["/bin/bash"]
diff --git a/contrib/docker/runtime/Dockerfile b/contrib/docker/runtime/Dockerfile
index 8fd62c21..324efa8f 100644
--- a/contrib/docker/runtime/Dockerfile
+++ b/contrib/docker/runtime/Dockerfile
@@ -1,7 +1,7 @@
 FROM debian
 
 RUN apt-get update
-RUN apt-get install -y curl
+RUN apt-get install -y curl libmosquitto1
 
 LABEL maintainer "ebusd@ebusd.eu"
 
@@ -11,7 +11,7 @@ RUN mkdir /etc/ebusd \
 
 ENV EBUSD_VERSION 3.0pre
 ENV EBUSD_ARCH amd64
-COPY ebusd-${EBUSD_VERSION}_${EBUSD_ARCH}.deb ebusd.deb
+COPY ebusd-${EBUSD_VERSION}_${EBUSD_ARCH}_mqtt1.deb ebusd.deb
 
 RUN dpkg -i ebusd.deb
 
@@ -19,4 +19,4 @@ EXPOSE 8888
 
 COPY docker-entrypoint.sh /
 ENTRYPOINT ["/docker-entrypoint.sh"]
-CMD ["-f", "--scanconfig"]
\ No newline at end of file
+CMD ["-f", "--scanconfig"]
diff --git a/contrib/docker/runtime/ebusd-3.0pre_amd64.deb b/contrib/docker/runtime/ebusd-3.0pre_amd64.deb
deleted file mode 100644
index f197c3cd..00000000
Binary files a/contrib/docker/runtime/ebusd-3.0pre_amd64.deb and /dev/null differ
diff --git a/contrib/docker/runtime/ebusd-3.0pre_amd64_mqtt1.deb b/contrib/docker/runtime/ebusd-3.0pre_amd64_mqtt1.deb
new file mode 100644
index 00000000..24af2b8f
Binary files /dev/null and b/contrib/docker/runtime/ebusd-3.0pre_amd64_mqtt1.deb differ