DOC: Clarify IPv4 address / mask notation rules
Adds some examples regarding shorthand IPv4 address notation which might
be confused with RFC 4632 CIDR notation, leading to different than
expected results.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 9602b37..7a3fff1 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -11473,6 +11473,21 @@
does not depend on any random DNS match at the moment the configuration is
parsed.
+The dotted IPv4 address notation is supported in both regular as well as the
+abbreviated form with all-0-octets omitted:
+
+ +------------------+------------------+------------------+
+ | Example 1 | Example 2 | Example 3 |
+ +------------------+------------------+------------------+
+ | 192.168.0.1 | 10.0.0.12 | 127.0.0.1 |
+ | 192.168.1 | 10.12 | 127.1 |
+ | 192.168.0.1/22 | 10.0.0.12/8 | 127.0.0.1/8 |
+ | 192.168.1/22 | 10.12/8 | 127.1/8 |
+ +------------------+------------------+------------------+
+
+Notice that this is different from RFC 4632 CIDR address notation in which
+192.168.42/24 would be equivalent to 192.168.42.0/24.
+
IPv6 may be entered in their usual form, with or without a netmask appended.
Only bit counts are accepted for IPv6 netmasks. In order to avoid any risk of
trouble with randomly resolved IP addresses, host names are never allowed in