Replace network solution with network add-on

Author: neha-viswanathan

content/en/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm.md

@@ -138,10 +138,10 @@ Right after `kubeadm init` there should not be any pods in these states.
 
 - If there are pods in one of these states _right after_ `kubeadm init`, please open an
   issue in the kubeadm repo. `coredns` (or `kube-dns`) should be in the `Pending` state
-  until you have deployed the network solution.
+  until you have deployed the network add-on.
 - If you see Pods in the `RunContainerError`, `CrashLoopBackOff` or `Error` state
-  after deploying the network solution and nothing happens to `coredns` (or `kube-dns`),
-  it's very likely that the Pod Network solution that you installed is somehow broken.
+  after deploying the network add-on and nothing happens to `coredns` (or `kube-dns`),
+  it's very likely that the Pod Network add-on that you installed is somehow broken.
   You might have to grant it more RBAC privileges or use a newer version. Please file
   an issue in the Pod Network providers' issue tracker and get the issue triaged there.
 - If you install a version of Docker older than 1.12.1, remove the `MountFlags=slave` option
@@ -152,14 +152,14 @@ Right after `kubeadm init` there should not be any pods in these states.
 ## `coredns` (or `kube-dns`) is stuck in the `Pending` state
 
 This is **expected** and part of the design. kubeadm is network provider-agnostic, so the admin
-should [install the pod network solution](/docs/concepts/cluster-administration/addons/)
+should [install the pod network add-on](/docs/concepts/cluster-administration/addons/)
 of choice. You have to install a Pod Network
 before CoreDNS may be deployed fully. Hence the `Pending` state before the network is set up.
 
 ## `HostPort` services do not work
 
 The `HostPort` and `HostIP` functionality is available depending on your Pod Network
-provider. Please contact the author of the Pod Network solution to find out whether
+provider. Please contact the author of the Pod Network add-on to find out whether
 `HostPort` and `HostIP` functionality are available.
 
 Calico, Canal, and Flannel CNI providers are verified to support HostPort.