Merge pull request #2369 from hashicorp/jbs-2204

Update getting started/join to address #2204

website/source/intro/getting-started/join.html.markdown

@@ -56,9 +56,10 @@ command-line option](/docs/agent/options.html#_node).
 We will also specify a [`bind` address](/docs/agent/options.html#_bind):
 this is the address that Consul listens on, and it *must* be accessible by
 all other nodes in the cluster. While a `bind` address is not strictly
-necessary (Consul will by default listen on the first private IP on a
-system), it's always best to provide one. Production servers often have
-multiple interfaces, so specifying a `bind` address assures that you will
+necessary, it's always best to provide one. Consul will by default attempt to
+listen on all IPv4 interfaces on a system, but will fail to start with an
+error if multiple private IPs are found. Since production servers often
+have multiple interfaces, specifying a `bind` address assures that you will
 never bind Consul to the wrong interface.
 
 The first node will act as our sole server in this cluster, and we indicate