Merge pull request #10312 from JacobTanenbaum/vxlan-docs

Adding vxlanPort changes to the docs

Author: Brice Fallon-Freeman

install_config/configuring_sdn.adoc

@@ -159,6 +159,37 @@ but not to *172.28.0.0/14*, because even though the original range is entirely
 inside the new range, the original range must be at the start of the CIDR. See
 xref:expanding-the-service-network[Expanding the service network] for more
 information.
+
+
+.Changing the VXLAN PORT for the cluster network
+
+A cluster administrator can change the VXLAN port the system uses by changing the vxlanPort variable in the
+master configuration file.
+
+----
+networkConfig:
+  clusterNetworks:
+  - cidr: 10.128.0.0/14
+    hostSubnetLength: 9
+  - cidr: 10.132.0.0/14
+    hostSubnetLength: 9
+  externalIPNetworkCIDRs: null
+  hostSubnetLength: 9
+  ingressIPNetworkCIDR: 172.29.0.0/16
+  networkPluginName: redhat/openshift-ovs-multitenant
+  serviceNetworkCIDR: 172.30.0.0/16
+  vxlanPort: 4789 <1>
+----
+<1> vxlanPort is the value used by the nodes for the VXLAN Port. It can be an integer between 1-65,535, if unspecified
+by the cluster administrator the default value is 4789.
+
+[IMPORTANT]
+====
+An administrator cannot change the VXLAN port of a running clusternetwork object. In order to change a cluster's VXLAN port
+it is required to delete the running clusternetwork, make the change in the master configuration file restart, the master and then
+restart all other nodes to fully propogate the change.
+====
+
 ====
 
 [[configuring-the-pod-network-on-nodes]]