document connection limit

Fixes #3395

site/concepts/network-topology.md

@@ -142,6 +142,13 @@ is not reachable, then the packet is dropped.  For most protocols
 (for example, TCP), the transmission will be retried a short time later, by
 which time the topology should have updated.
 
+#### connection limit
+
+In a fully connected mesh of N peers, this would mean N^2 connections. To constrain the resource consumption and 
+communication between the peers and complexity of route calculation there is a configurable upper limit on the 
+maximum number of connections that a peer can make to the remote peers. There is safe default value (100) which works
+for most deployment. However if you would like to increase the number of peers, you should be able to explicitly override the
+default value by setting the CONN_LIMIT environment variable or explicitly invoking weave launch like `weave launch --connlimit=100`.
 
 **See Also**
 

site/kubernetes/kube-addon.md

@@ -376,7 +376,7 @@ The list of variables you can set is:
 * `CHECKPOINT_DISABLE` - if set to 1, disable checking for new Weave Net
   versions (default is blank, i.e. check is enabled)
 * `CONN_LIMIT` - soft limit on the number of connections between
-  peers. Defaults to 30.
+  peers. Defaults to 100.
 * `HAIRPIN_MODE` - Weave Net defaults to enabling hairpin on the bridge side of
   the `veth` pair for containers attached. If you need to disable hairpin, e.g. your
   kernel is one of those that can panic if hairpin is enabled, then you can disable it