diff --git a/README.md b/README.md
index a6b1de5..31ba421 100755
--- a/README.md
+++ b/README.md
@@ -140,8 +140,9 @@
 Note: The [son-push](https://github.com/mpeuster/son-cli) tool can be used instead of CURL.
 
 
-### CLI Commands
+### Further Documentation
 * [Full CLI command documentation](https://github.com/sonata-nfv/son-emu/wiki/CLI-Command-Overview)
+* [Requirements for Docker containers executed by the emulator](https://github.com/sonata-nfv/son-emu/wiki/Container-Requirements)
 
 ## License
 
diff --git a/src/emuvim/api/sonata/dummygatekeeper.py b/src/emuvim/api/sonata/dummygatekeeper.py
index 20150d0..432c134 100755
--- a/src/emuvim/api/sonata/dummygatekeeper.py
+++ b/src/emuvim/api/sonata/dummygatekeeper.py
@@ -105,7 +105,10 @@
         self.local_docker_files = dict()
         self.remote_docker_image_urls = dict()
         self.instances = dict()
-        self.vnfname2num = dict()
+        self.vnf_name2docker_name = dict()
+        # lets generate a set of subnet configurations used for e-line chaining setup
+        self.eline_subnets_src = generate_subnet_strings(50, start=200, subnet_size=24, ip=1)
+        self.eline_subnets_dst = generate_subnet_strings(50, start=200, subnet_size=24, ip=2)
 
     def onboard(self):
         """
@@ -154,31 +157,46 @@
             self.instances[instance_uuid]["vnf_instances"].append(vnfi)
 
         # 3. Configure the chaining of the network functions (currently only E-Line links supported)
-        nfid2name = defaultdict(lambda :"NotExistingNode", 
-                                reduce(lambda x,y: dict(x, **y),
-                                       map(lambda d:{d["vnf_id"]:d["vnf_name"]},
+        vnf_id2vnf_name = defaultdict(lambda: "NotExistingNode",
+                                reduce(lambda x, y: dict(x, **y),
+                                       map(lambda d: {d["vnf_id"]: d["vnf_name"]},
                                            self.nsd["network_functions"])))
         
         vlinks = self.nsd["virtual_links"]
         fwd_links = self.nsd["forwarding_graphs"][0]["constituent_virtual_links"]
         eline_fwd_links = [l for l in vlinks if (l["id"] in fwd_links) and (l["connectivity_type"] == "E-Line")]
 
-        cookie = 1 # not clear why this is needed - to check with Steven
+        cookie = 1  # not clear why this is needed - to check with Steven
         for link in eline_fwd_links:
-            src_node, src_port = link["connection_points_reference"][0].split(":")
-            dst_node, dst_port = link["connection_points_reference"][1].split(":")
+            src_id, src_if_name = link["connection_points_reference"][0].split(":")
+            dst_id, dst_if_name = link["connection_points_reference"][1].split(":")
 
-            srcname = nfid2name[src_node]
-            dstname = nfid2name[dst_node]
-            LOG.debug("src name: "+srcname+" dst name: "+dstname)
+            src_name = vnf_id2vnf_name[src_id]
+            dst_name = vnf_id2vnf_name[dst_id]
 
-            if (srcname in self.vnfds) and (dstname in self.vnfds) :
-                network = self.vnfds[srcname].get("dc").net  # there should be a cleaner way to find the DCNetwork
-                src_vnf = self.vnfname2num[srcname]
-                dst_vnf = self.vnfname2num[dstname]
-                ret = network.setChain(src_vnf, dst_vnf, vnf_src_interface=src_port, vnf_dst_interface=dst_port, bidirectional = True, cmd="add-flow", cookie = cookie)
+            LOG.debug(
+                "Setting up E-Line link. %s(%s:%s) -> %s(%s:%s)" % (
+                    src_name, src_id, src_if_name, dst_name, dst_id, dst_if_name))
+
+            if (src_name in self.vnfds) and (dst_name in self.vnfds):
+                network = self.vnfds[src_name].get("dc").net  # there should be a cleaner way to find the DCNetwork
+                src_docker_name = self.vnf_name2docker_name[src_name]
+                dst_docker_name = self.vnf_name2docker_name[dst_name]
+                LOG.debug(src_docker_name)
+                ret = network.setChain(
+                    src_docker_name, dst_docker_name,
+                    vnf_src_interface=src_if_name, vnf_dst_interface=dst_if_name,
+                    bidirectional=True, cmd="add-flow", cookie=cookie)
                 cookie += 1
 
+                # re-configure the VNFs IP assignment and ensure that a new subnet is used for each E-Link
+                src_vnfi = self._get_vnf_instance(instance_uuid, src_name)
+                if src_vnfi is not None:
+                    self._vnf_reconfigure_network(src_vnfi, src_if_name, self.eline_subnets_src.pop(0))
+                dst_vnfi = self._get_vnf_instance(instance_uuid, dst_name)
+                if dst_vnfi is not None:
+                    self._vnf_reconfigure_network(dst_vnfi, dst_if_name, self.eline_subnets_dst.pop(0))
+
         # 4. run the emulator specific entrypoint scripts in the VNFIs of this service instance
         self._trigger_emulator_start_scripts_in_vnfis(self.instances[instance_uuid]["vnf_instances"])
 
@@ -207,11 +225,46 @@
             # 3. do the dc.startCompute(name="foobar") call to run the container
             # TODO consider flavors, and other annotations
             intfs = vnfd.get("connection_points")
-            self.vnfname2num[vnf_name] = GK.get_next_vnf_name()
-            LOG.info("VNF "+vnf_name+" mapped to "+self.vnfname2num[vnf_name]+" on dc "+str(vnfd.get("dc")))
-            vnfi = target_dc.startCompute(self.vnfname2num[vnf_name], network=intfs, image=docker_name, flavor_name="small")
+            self.vnf_name2docker_name[vnf_name] = GK.get_next_vnf_name()
+            LOG.info("Starting %r as %r in DC %r" % (vnf_name, self.vnf_name2docker_name[vnf_name], vnfd.get("dc")))
+            LOG.debug("Interfaces for %r: %r" % (vnf_name, intfs))
+            vnfi = target_dc.startCompute(self.vnf_name2docker_name[vnf_name], network=intfs, image=docker_name, flavor_name="small")
             return vnfi
 
+    def _get_vnf_instance(self, instance_uuid, name):
+        """
+        Returns the Docker object for the given VNF name (or Docker name).
+        :param instance_uuid: UUID of the service instance to search in.
+        :param name: VNF name or Docker name. We are fuzzy here.
+        :return:
+        """
+        dn = name
+        if name in self.vnf_name2docker_name:
+            dn = self.vnf_name2docker_name[name]
+        for vnfi in self.instances[instance_uuid]["vnf_instances"]:
+            if vnfi.name == dn:
+                return vnfi
+        LOG.warning("No container with name: %r found.")
+        return None
+
+    @staticmethod
+    def _vnf_reconfigure_network(vnfi, if_name, net_str):
+        """
+        Reconfigure the network configuration of a specific interface
+        of a running container.
+        :param vnfi: container instacne
+        :param if_name: interface name
+        :param net_str: network configuration string, e.g., 1.2.3.4/24
+        :return:
+        """
+        intf = vnfi.intf(intf=if_name)
+        if intf is not None:
+            intf.setIP(net_str)
+            LOG.debug("Reconfigured network of %s:%s to %r" % (vnfi.name, if_name, net_str))
+        else:
+            LOG.warning("Interface not found: %s:%s. Network reconfiguration skipped." % (vnfi.name, if_name))
+
+
     def _trigger_emulator_start_scripts_in_vnfis(self, vnfi_list):
         for vnfi in vnfi_list:
             config = vnfi.dcinfo.get("Config", dict())
@@ -409,6 +462,7 @@
         Return a list of UUID's of uploaded service packages.
         :return: dict/list
         """
+        LOG.info("GET /packages")
         return {"service_uuid_list": list(GK.services.iterkeys())}
 
 
@@ -440,7 +494,8 @@
         Returns a list of UUIDs containing all running services.
         :return: dict / list
         """
-        return {"service_instance_list": [
+        LOG.info("GET /instantiations")
+        return {"service_instantiations_list": [
             list(s.instances.iterkeys()) for s in GK.services.itervalues()]}
 
 
@@ -488,6 +543,16 @@
     return path
 
 
+def generate_subnet_strings(n, start=1, subnet_size=24, ip=0):
+    """
+    Helper to generate different network configuration strings.
+    """
+    r = list()
+    for i in range(start, start + n):
+        r.append("%d.0.0.%d/%d" % (i, ip, subnet_size))
+    return r
+
+
 if __name__ == '__main__':
     """
     Lets allow to run the API in standalone mode.
diff --git a/src/emuvim/cli/rest/network.py b/src/emuvim/cli/rest/network.py
index 86ed92b..4f6a32d 100755
--- a/src/emuvim/cli/rest/network.py
+++ b/src/emuvim/cli/rest/network.py
@@ -117,7 +117,7 @@
     "--match", "-m", dest="match",
     help="string holding extra matches for the flow entries")
 parser.add_argument(
-    "--bidirectional", "-b", dest="bidirectional",
+    "--bidirectional", "-b", dest="bidirectional", action='store_true',
     help="add/remove the flow entries from src to dst and back")
 parser.add_argument(
     "--cookie", "-c", dest="cookie",
diff --git a/src/emuvim/dcemulator/net.py b/src/emuvim/dcemulator/net.py
index 2c5ce14..cbe668f 100755
--- a/src/emuvim/dcemulator/net.py
+++ b/src/emuvim/dcemulator/net.py
@@ -39,11 +39,15 @@
 from mininet.node import Controller, DefaultController, OVSSwitch, OVSKernelSwitch, Docker, RemoteController
 from mininet.cli import CLI
 from mininet.link import TCLink
+from mininet.clean import cleanup
 import networkx as nx
 from emuvim.dcemulator.monitoring import DCNetworkMonitor
 from emuvim.dcemulator.node import Datacenter, EmulatorCompute
 from emuvim.dcemulator.resourcemodel import ResourceModelRegistrar
 
+LOG = logging.getLogger("dcemulator.net")
+LOG.setLevel(logging.DEBUG)
+
 class DCNetwork(Containernet):
     """
     Wraps the original Mininet/Containernet class and provides
@@ -63,20 +67,19 @@
         :param kwargs: path through for Mininet parameters
         :return:
         """
+        # members
         self.dcs = {}
+        self.ryu_process = None
 
-        # make sure any remaining Ryu processes are killed
+        # always cleanup environment before we start the emulator
         self.killRyu()
-        # make sure no containers are left over from a previous emulator run.
-        self.removeLeftoverContainers()
+        cleanup()
 
         # call original Docker.__init__ and setup default controller
         Containernet.__init__(
             self, switch=OVSKernelSwitch, controller=controller, **kwargs)
 
-
         # Ryu management
-        self.ryu_process = None
         if controller == RemoteController:
             # start Ryu controller
             self.startRyu(learning_switch=enable_learning)
@@ -115,7 +118,7 @@
         dc.net = self  # set reference to network
         self.dcs[label] = dc
         dc.create()  # finally create the data center in our Mininet instance
-        logging.info("added data center: %s" % label)
+        LOG.info("added data center: %s" % label)
         return dc
 
     def addLink(self, node1, node2, **params):
@@ -125,7 +128,7 @@
         """
         assert node1 is not None
         assert node2 is not None
-        logging.debug("addLink: n1=%s n2=%s" % (str(node1), str(node2)))
+        LOG.debug("addLink: n1=%s n2=%s" % (str(node1), str(node2)))
         # ensure type of node1
         if isinstance( node1, basestring ):
             if node1 in self.dcs:
@@ -252,7 +255,7 @@
         Containernet.stop(self)
 
         # stop Ryu controller
-        self.stopRyu()
+        self.killRyu()
 
 
     def CLI(self):
@@ -279,6 +282,14 @@
 
     def _chainAddFlow(self, vnf_src_name, vnf_dst_name, vnf_src_interface=None, vnf_dst_interface=None, **kwargs):
 
+        src_sw = None
+        dst_sw = None
+        src_sw_inport_nr = 0
+        dst_sw_outport_nr = 0
+
+        LOG.debug("call chainAddFlow vnf_src_name=%r, vnf_src_interface=%r, vnf_dst_name=%r, vnf_dst_interface=%r",
+                  vnf_src_name, vnf_src_interface, vnf_dst_name, vnf_dst_interface)
+
         #check if port is specified (vnf:port)
         if vnf_src_interface is None:
             # take first interface by default
@@ -289,10 +300,10 @@
         for connected_sw in self.DCNetwork_graph.neighbors(vnf_src_name):
             link_dict = self.DCNetwork_graph[vnf_src_name][connected_sw]
             for link in link_dict:
-                if link_dict[link]['src_port_id'] == vnf_src_interface:
+                if (link_dict[link]['src_port_id'] == vnf_src_interface or
+                        link_dict[link]['src_port_name'] == vnf_src_interface):  # Fix: we might also get interface names, e.g, from a son-emu-cli call
                     # found the right link and connected switch
                     src_sw = connected_sw
-
                     src_sw_inport_nr = link_dict[link]['dst_port_nr']
                     break
 
@@ -306,7 +317,8 @@
         for connected_sw in self.DCNetwork_graph.neighbors(vnf_dst_name):
             link_dict = self.DCNetwork_graph[connected_sw][vnf_dst_name]
             for link in link_dict:
-                if link_dict[link]['dst_port_id'] == vnf_dst_interface:
+                if link_dict[link]['dst_port_id'] == vnf_dst_interface or \
+                        link_dict[link]['dst_port_name'] == vnf_dst_interface:  # Fix: we might also get interface names, e.g, from a son-emu-cli call
                     # found the right link and connected switch
                     dst_sw = connected_sw
                     dst_sw_outport_nr = link_dict[link]['src_port_nr']
@@ -319,10 +331,15 @@
             # if all shortest paths are wanted, use: all_shortest_paths
             path = nx.shortest_path(self.DCNetwork_graph, src_sw, dst_sw, weight=kwargs.get('weight'))
         except:
-            logging.info("No path could be found between {0} and {1}".format(vnf_src_name, vnf_dst_name))
+            LOG.exception("No path could be found between {0} and {1} using src_sw={2} and dst_sw={3}".format(
+                vnf_src_name, vnf_dst_name, src_sw, dst_sw))
+            LOG.debug("Graph nodes: %r" % self.DCNetwork_graph.nodes())
+            LOG.debug("Graph edges: %r" % self.DCNetwork_graph.edges())
+            for e, v in self.DCNetwork_graph.edges():
+                LOG.debug("%r" % self.DCNetwork_graph[e][v])
             return "No path could be found between {0} and {1}".format(vnf_src_name, vnf_dst_name)
 
-        logging.info("Path between {0} and {1}: {2}".format(vnf_src_name, vnf_dst_name, path))
+        LOG.info("Path between {0} and {1}: {2}".format(vnf_src_name, vnf_dst_name, path))
 
         current_hop = src_sw
         switch_inport_nr = src_sw_inport_nr
@@ -347,9 +364,9 @@
 
             if next_hop == vnf_dst_name:
                 switch_outport_nr = dst_sw_outport_nr
-                logging.info("end node reached: {0}".format(vnf_dst_name))
+                LOG.info("end node reached: {0}".format(vnf_dst_name))
             elif not isinstance( next_node, OVSSwitch ):
-                logging.info("Next node: {0} is not a switch".format(next_hop))
+                LOG.info("Next node: {0} is not a switch".format(next_hop))
                 return "Next node: {0} is not a switch".format(next_hop)
             else:
                 # take first link between switches by default
@@ -479,7 +496,7 @@
             ofcmd = ''
 
         node.dpctl(cmd, ofcmd)
-        logging.info("{3} in switch: {0} in_port: {1} out_port: {2}".format(node.name, switch_inport_nr,
+        LOG.info("{3} in switch: {0} in_port: {1} out_port: {2}".format(node.name, switch_inport_nr,
                                                                                  switch_outport_nr, cmd))
 
     # start Ryu Openflow controller as Remote Controller for the DCNetwork
@@ -501,19 +518,16 @@
             self.ryu_process = Popen([ryu_cmd, ryu_path2, ryu_option, ryu_of_port], stdout=FNULL, stderr=FNULL)
         time.sleep(1)
 
-    def stopRyu(self):
+    def killRyu(self):
+        """
+        Stop the Ryu controller that might be started by son-emu.
+        :return:
+        """
+        # try it nicely
         if self.ryu_process is not None:
             self.ryu_process.terminate()
             self.ryu_process.kill()
-        self.killRyu()
-
-    @staticmethod
-    def removeLeftoverContainers():
-        # TODO can be more python-based using eg. docker-py?
-        Popen('docker ps -a -q --filter="name=mn.*" | xargs -r docker rm -f', shell=True)
-
-    @staticmethod
-    def killRyu():
+        # ensure its death ;-)
         Popen(['pkill', '-f', 'ryu-manager'])
 
     def ryu_REST(self, prefix, dpid=None, data=None):
@@ -523,7 +537,7 @@
             else:
                 url = self.ryu_REST_api + '/' + str(prefix)
             if data:
-                #logging.info('POST: {0}'.format(str(data)))
+                #LOG.info('POST: {0}'.format(str(data)))
                 req = urllib2.Request(url, str(data))
             else:
                 req = urllib2.Request(url)
@@ -531,8 +545,8 @@
             ret = urllib2.urlopen(req).read()
             return ret
         except:
-            logging.info('error url: {0}'.format(str(url)))
-            if data: logging.info('error POST: {0}'.format(str(data)))
+            LOG.info('error url: {0}'.format(str(url)))
+            if data: LOG.info('error POST: {0}'.format(str(data)))
 
     # need to respect that some match fields must be integers
     # http://ryu.readthedocs.io/en/latest/app/ofctl_rest.html#description-of-match-and-actions
diff --git a/src/emuvim/dcemulator/node.py b/src/emuvim/dcemulator/node.py
index b29d634..b88913b 100755
--- a/src/emuvim/dcemulator/node.py
+++ b/src/emuvim/dcemulator/node.py
@@ -32,7 +32,7 @@
 import time
 import json
 
-LOG = logging.getLogger("dcemulator")
+LOG = logging.getLogger("dcemulator.node")
 LOG.setLevel(logging.DEBUG)
 
 
@@ -191,6 +191,9 @@
         # if no --net option is given, network = [{}], so 1 empty dict in the list
         # this results in 1 default interface with a default ip address
         for nw in network:
+            # clean up network configuration (e.g. RTNETLINK does not allow ':' in intf names
+            if nw.get("id") is not None:
+                nw["id"] = self._clean_ifname(nw["id"])
             # TODO we cannot use TCLink here (see: https://github.com/mpeuster/containernet/issues/3)
             self.net.addLink(d, self.switch, params1=nw, cls=Link, intfName1=nw.get('id'))
         # do bookkeeping
@@ -256,3 +259,19 @@
         self.net.rm_registrar.register(self, rm)
         LOG.info("Assigned RM: %r to DC: %r" % (rm, self))
 
+    @staticmethod
+    def _clean_ifname(name):
+        """
+        Cleans up given string to be a
+        RTNETLINK compatible interface name.
+        :param name: string
+        :return: string
+        """
+        if name is None:
+            return "if0"
+        name = name.replace(":", "-")
+        name = name.replace(" ", "-")
+        name = name.replace(".", "-")
+        name = name.replace("_", "-")
+        return name
+
diff --git a/src/emuvim/examples/sonata_y1_demo_topology_1.py b/src/emuvim/examples/sonata_y1_demo_topology_1.py
index c5c9611..1792f88 100755
--- a/src/emuvim/examples/sonata_y1_demo_topology_1.py
+++ b/src/emuvim/examples/sonata_y1_demo_topology_1.py
@@ -43,7 +43,7 @@
 
 def create_topology1():
     # create topology
-    net = DCNetwork(controller=RemoteController, monitor=False, enable_learning = False)
+    net = DCNetwork(controller=RemoteController, monitor=False, enable_learning=False)
     dc1 = net.addDatacenter("dc1")
     dc2 = net.addDatacenter("dc2")
     s1 = net.addSwitch("s1")
@@ -52,6 +52,7 @@
 
     # add the command line interface endpoint to each DC (REST API)
     rapi1 = RestApiEndpoint("0.0.0.0", 5001)
+    rapi1.connectDCNetwork(net)
     rapi1.connectDatacenter(dc1)
     rapi1.connectDatacenter(dc2)
     # run API endpoint server (in another thread, don't block)