diff --git a/Makefile b/Makefile
index a084f5f..7e572d9 100644
--- a/Makefile
+++ b/Makefile
@@ -49,7 +49,7 @@
 	mdl -s $(LINT_STYLE) `find -L . ! -path "./partials/*" ! -path "./_book/*" ! -path "./repos/*"  ! -path "./node_modules/*" ! -path "./cord-tester/modules/*" -name "*.md"`
 
 linkcheck: $(ALL_DOCS) _book
-	linkchecker -a _book/
+	linkchecker -a --check-extern _book/
 
 # Host holding the git server
 REPO_HOST   ?= https://gerrit.opencord.org
@@ -87,3 +87,13 @@
 swagger: xos
 	pushd repos/xos/docs; make swagger_docs; popd;
 
+# generate a list of git checksums suitable for updating git_refs
+freeze: repos
+	@for repo in $(OTHER_REPO_DOCS) ; do \
+	  GIT_SUBDIR=`grep "^$$repo " git_refs | awk '{print $$2}'` ;\
+	  cd "repos/$$repo" > /dev/null ;\
+	    HEAD_SHA=`git rev-parse HEAD` ;\
+	    printf "%-21s %-8s %-40s\n" $$repo $$GIT_SUBDIR $$HEAD_SHA ;\
+	  cd ../.. ;\
+	done
+
diff --git a/SUMMARY.md b/SUMMARY.md
index 5da0124..ba8f447 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -20,8 +20,8 @@
     * [Fabric Software Setup](fabric-setup.md)
     * [Bringing Up CORD](profiles/intro.md)
         * [R-CORD](profiles/rcord/install.md)
-            * [OLT Setup](openolt/README.md)
-                * [Emulated OLT/ONU](profiles/rcord/emulate.md)
+            * [EdgeCore (OpenOLT driver) Setup](openolt/README.md)
+            * [Emulated OLT/ONU](profiles/rcord/emulate.md)
         * [M-CORD](profiles/mcord/install.md)
             * [EnodeB Setup](profiles/mcord/enodeb-setup.md)
     * [Helm Reference](charts/helm.md)
@@ -53,6 +53,7 @@
         * [RCORD](rcord/README.md)
         * [vOLT](olt-service/README.md)
         * [vRouter](vrouter/README.md)
+    * [Attach containers to external NICs](operating_cord/veth_intf.md)
 * [Development Guide](developer/developer.md)
     * [Getting the Source Code](developer/getting_the_code.md)
     * [Writing Models and Synchronizers](xos/intro.md)
diff --git a/book.json b/book.json
index fd3f609..1317bf7 100644
--- a/book.json
+++ b/book.json
@@ -21,6 +21,10 @@
           "text": "Master (Devel)"
         },
         {
+          "value": "/cord-6.0",
+          "text": "6.0 (Stable)"
+        },
+        {
           "value": "/cord-5.0",
           "text": "5.0 (Stable)"
         },
@@ -29,10 +33,6 @@
           "text": "4.1 (Stable)"
         },
         {
-          "value": "/cord-4.0",
-          "text": "4.0 (Stable)"
-        },
-        {
           "value": "https://wiki.opencord.org/display/CORD/Building+and+Installing+CORD",
           "text": "3.0 and previous (wiki)"
         }
diff --git a/charts/kafka.md b/charts/kafka.md
index 051754d..464dfe5 100644
--- a/charts/kafka.md
+++ b/charts/kafka.md
@@ -7,7 +7,12 @@
 
 ```shell
 helm repo add incubator http://storage.googleapis.com/kubernetes-charts-incubator
-helm install --name cord-kafka incubator/kafka
+helm install --name cord-kafka \
+--set replicas=1 \
+--set persistence.enabled=false \
+--set zookeeper.servers=1 \
+--set zookeeper.persistence.enabled=false \
+incubator/kafka
 ```
 
 If you are experierencing problems with a multi instance installation of kafka,
diff --git a/fabric-setup.md b/fabric-setup.md
index d0de4c2..4fb19b6 100644
--- a/fabric-setup.md
+++ b/fabric-setup.md
@@ -45,6 +45,7 @@
 Three OFDPA drivers are available:
 
 * [EdgeCore 5712-54X / 5812-54X / 6712-32X](https://github.com/onfsdn/atrium-docs/blob/master/16A/ONOS/builds/ofdpa_3.0.5.5%2Baccton1.7-1_amd64.deb?raw=true) - *checksum: sha256:db228b6e79fb15f77497b59689235606b60abc157e72fc3356071bcc8dc4c01f*
+* [EdgeCore 7712-32X](https://github.com/onfsdn/atrium-docs/blob/master/16A/ONOS/builds/ofdpa_3.0.5.5%2Baccton1.7-1_amd64.deb) - *checksum: sha256:4f78e8f43976dc86ab1cdc2f98afa743ce2e0cc5923e429c91f96b0edc3ddf4b*
 * [QuantaMesh T3048-LY8](https://github.com/onfsdn/atrium-docs/blob/master/16A/ONOS/builds/ofdpa-ly8_0.3.0.5.0-EA5-qct-01.01_amd64.deb?raw=true) - *checksum: sha256:f8201530b1452145c1a0956ea1d3c0402c3568d090553d0d7b3c91a79137da9e*
 * [QuantaMesh BMS T7032-IX1/IX1B](https://github.com/onfsdn/atrium-docs/blob/master/16A/ONOS/builds/ofdpa-ix1_0.3.0.5.0-EA5-qct-01.00_amd64.deb?raw=true) *checksum: sha256:278b8ffed8a8fc705a1b60d16f8e70377e78342a27a11568a1d80b1efd706a46*
 
diff --git a/operating_cord/rest_apis.md b/operating_cord/rest_apis.md
index 5f3f476..692aaa0 100644
--- a/operating_cord/rest_apis.md
+++ b/operating_cord/rest_apis.md
@@ -8,4 +8,4 @@
 
 You can access the REST API specification on a running POD by going to
 the `/apidocs/` URL on the Chameleon REST endpoint (exposed at
-port 30006 by default): <http://pod-ip-or-dns-address:30006/apidocs/>.
+port 30006 by default): `http://pod-ip-or-dns-address:30006/apidocs/`.
diff --git a/operating_cord/veth_intf.md b/operating_cord/veth_intf.md
new file mode 100644
index 0000000..4ccf526
--- /dev/null
+++ b/operating_cord/veth_intf.md
@@ -0,0 +1,112 @@
+# Manually connect containers to a network card
+
+Sometimes you may need to attach some containers NICs to the network cards of the machines hosting them, for example to run some data plane traffic through them.
+
+Although CORD doesn't fully support this natively there are some (hackish) ways to do this manually.
+
+## Create a bridge and a veth
+
+The easiest way to do this is to skip Kubernetes and directly attach the Docker container link it to the host network interface, through a Virtual Ethernet Interface Pair (veth pair).
+
+Let's see how.
+
+For completeness, let's assume you're running a three nodes Kubernetes deployment, and that you're trying to attach a container *already deployed* called *vcore-5b4c5478f-lxrpb* to a physical interface *eth1* (already existing on one of the three hosts, running your container). The virtual interface inside the container will be called *eth2*.
+
+You got the name of the container running
+
+```shell
+$ kubectl get pods [-n NAMESPACE]
+NAME                      READY     STATUS    RESTARTS   AGE
+vcore-5b4c5478f-lxrpb     1/1       Running   1          7d
+```
+
+Find out on which of the three nodes the container has been deployed
+
+```shell
+$ kubectl describe pod  vcore-5b4c5478f-lxrpb | grep Node
+Node:           node3/10.90.0.103
+Node-Selectors:  <none>
+```
+As you can see from the first line, the container has been deployed by Kubernetes on the Docker daemon running on node 3 (this is just an example). In this case, with IP *10.90.0.103*.
+
+Let's SSH into the node and let's look for the specific Docker container ID
+
+```shell
+$ container_id=$(sudo docker ps | grep vcore-5b4c5478f-lxrpb | head -n 1 | awk '{print $1}')
+85fed7deea7b
+```
+
+The interface on the hosting machine should be turned off first
+
+```shell
+sudo ip link set eth1 down
+```
+
+Create a veth called *veth0* and let's add to it the new virtual interface *eth2*
+
+```shell
+sudo ip link add veth0 type veth peer name eth2
+```
+
+Add the virtual network interface *eth2* to the container namespace
+
+```shell
+sudo ip link set eth2 netns ${container_id}
+```
+
+Bring up the virtual interface
+
+```shell
+sudo ip netns exec ${container_id} ip link set eth2 up
+```
+
+Bring up *veth0*
+
+```shell
+sudo ip link set veth0 up
+```
+
+Create a bridge named *br1*. Add *veth0* to it and the host interface *eth1*
+
+```shell
+sudo ip link add br1 type bridge
+sudo ip link set veth0 master br1
+sudo ip link set eth1 master br1
+
+```
+
+Bring up again the host interface and the bridge
+
+```shell
+sudo ip link set eth1 up
+sudo ip link set br1 up
+```
+
+At this point, you should see an additional interface *eth2* inside the container
+
+```shell
+$ kubectl exec -it vcore-5b4c5478f-lxrpb /bin/bash
+$ ip link show
+$ node3:~$ ip link show
+1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1
+    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
+2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
+    link/ether c4:54:44:8f:b7:74 brd ff:ff:ff:ff:ff:ff
+3: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
+    link/ether d6:84:33:2f:8c:92 brd ff:ff:ff:ff:ff:ff
+```
+
+## Cleanup (remove veth and bridge)
+
+As a follow up of the previous example, let's now try to delete what has been created so far, to bring the system back to the original state.
+
+```shell
+ip link set veth0 down
+ip link delete veth0
+ip netns exec ${container_id} ip link set eth2 down
+ip netns exec ${container_id} ip link delete eth2
+ip link set eth1 down
+ip link set br1 down
+brctl delbr br1
+ip link set eth1 up
+```