Notes on virtual network testing environment.

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+What We Have
+============
+
+./build.sh
+----------
+
+First, as root, run the ./build.sh script.  This will use the _tuntap_ subcommand
+of _ip_ in order to create a variety of virtual interfaces.  It then will assign to
+each of these a unique address of the form:
+
+        inum.vnum.99.99
+
+where _inum_ is between 80 and 95 and _vnum_ is either 88 or, if your wlan0
+interface is on an IPv4 lan, the very last component of your wlan0 IP address.
+For example, if wlan0 has address 192.168.5.33, then _vnum_ will be 33.  This
+allows multiple test environments to coexist on a lan and, provided routing
+tables allow it, be routable from each other.
+
+Note that the ip addresses of the testing environment are chosen from the pool
+that RFCs assign to actual global internet addresses rather from one of the
+reserved local lan domains.  This is because the software algorithms may want
+to recognize lan domains and treat them specially, so we want to simulate the
+appearance of actual internet peers.
+
+
+./run.sh
+--------
+
+Next, make a symlink (named "dhtd") in the _vnet_ folder to the dhtd binary.
+And run the ./run.sh script.  You do not need root.  This will create a
+detached _screen_ session where each window is running a different instance of
+the dhtd daemon with a different working directory.  Each instance will bind to
+a different inum.vnum.99.99 ip address created by the ./build.sh script.
+
+./everywhere.sh
+---------------
+
+To run the same command in every one of the running test instances, you may use
+the ./everywhere.sh script.  It's command line arguments are expected to be a
+shell command that will be run repeatedly from within the working directory of
+each of the running dhtd daemons.  Since this is a shell command and not a dht
+command, you may need to specify the path to the dht client binary as the first
+argument.
+
+./clean.sh
+----------
+
+After issuing "stop" to all the dhtd instances, you may want to clean up and
+remove all the working directories and network interfaces.  To accomplish this,
+as root, run the ./clean.sh script.
+
+Note:  You probably do not want to run build.sh and clean.sh repeatedly if you
+are testing changes to the dhtd program as you can simply, without root, use
+./run.sh to re-launch a modified version of the daemon.
+
+
+What We Want
+============
+
+We want to test TCP-only connectivity.  This means some combination of iptables
+and possibly the cgroups commands to create more controlled virtual network
+environments.  The following man pages are relevant:
+
+  man 4 veth
+  man 2 clone
+  man 8 iptables
+  man 7 cgroups
+
+We need to bootstrap an instance of dhtd off of our test network and also an
+instance of uTox (or some other toxcore-based client) and get them to build a
+TCP-mediated link.  This would, of course, disabling UDP in one or both of the
+clients either by a hardcoded temporary source code patch or through iptables
+rules.