add the assumption

Author: vladak

network.tex

@@ -1061,10 +1061,10 @@
 \item IPv6 sockets may be used for both IPv4 and IPv6 communications.  That
 means if you try to bind addresses returned by \funnm{getaddrinfo}, \funnm{bind}
 should return \texttt{EADDRINUSE} after its first call if you use both IPv4 and
-IPv6 addresses.  Binding an IPv6 address should be sufficient to accept
-connections over IPv4 as well.  Details are in RFC~3493.  If you want to
-restrict a socket to IPv6 only, use the following code on a socket from the
-\texttt{AF\_INET6} family:
+IPv6 addresses, assuming the IPv6 address is returned first.
+Binding an IPv6 address should be sufficient to accept connections over IPv4
+as well.  Details are in RFC~3493.  If you want to restrict a socket to IPv6
+only, use the following code on a socket from the \texttt{AF\_INET6} family:
 
 \begin{verbatim}
       int on = 1;