If running a docker-container you have a network of your own per container. If you want to use the host-system's network instead you can use the --net=host option.

In this sample you call the docker containers arangodb arangoimp-call and connect with which would not be possible if not using --net=host e.g.:

sudo docker run --net=host --rm --volumes-from arangodb-data_3.0 \
    -v $(pwd):/backup arangodb:3.0.4 /usr/bin/arangoimp \
    --server.endpoint tcp:// --server.database pwatch \
    --server.username uname --server.password pass