[DOC] update IPv6 support for bind
diff --git a/doc/configuration.txt b/doc/configuration.txt
index fa5038f..d06ad98 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -1422,7 +1422,7 @@
address, or '*'. It designates the address the frontend will
listen on. If unset, all IPv4 addresses of the system will be
listened on. The same will apply for '*' or the system's
- special address "0.0.0.0".
+ special address "0.0.0.0". The IPv6 equivalent is '::'.
<port_range> is either a unique TCP port, or a port range for which the
proxy will accept connections for the IP address specified