README/sshuttle.1: add a note about the MacOS kernel bug.

And its side effects.

Reported by David Held / Antonio d'Souza.

README.md

+
+WARNING:
+On MacOS 10.6 (at least up to 10.6.6), your network will
+stop responding about 10 minutes after the first time you
+start sshuttle, because of a MacOS kernel bug relating to
+arp and the net.inet.ip.scopedroute sysctl.  To fix it,
+just switch your wireless off and on. Sshuttle makes the
+kernel setting it changes permanent, so this won't happen
+again, even after a reboot.
+
+
 sshuttle: where transparent proxy meets VPN meets ssh
 =====================================================
 

sshuttle.md

@@ -253,6 +253,17 @@ between the two separate streams, so a tcp-based tunnel is
 fine.
 
 
+# BUGS
+
+On MacOS 10.6 (at least up to 10.6.6), your network will
+stop responding about 10 minutes after the first time you
+start sshuttle, because of a MacOS kernel bug relating to
+arp and the net.inet.ip.scopedroute sysctl.  To fix it,
+just switch your wireless off and on. Sshuttle makes the
+kernel setting it changes permanent, so this won't happen
+again, even after a reboot.
+
+
 # SEE ALSO
 
 `ssh`(1), `python`(1)