ejabberd mod_register allow registration only from a specified IP - configuration

Question

I'm trying to get ejabberd to allow for in-channel registration only from a specific IP, using mod_register's ip_access clause.
To do this, I added this line to the mod_register block in my ejabberd.cfg:
{ip_access, [{allow, "the.allowed.ip.address"}]}
... And restarted ejabberd via ejabberdctl restart. The server came back online with no warnings or errors logged in /var/log/ejabberd/ejabberd.log.
Unfortunately, with this line of code, I could still perform in-channel registration from a non-whitelisted IP using Adium as a client. I decided to amend the line above by adding:
{ip_access, [{allow, "the.allowed.ip.address"}, {deny, all}]}
... Running the risk of causing all registrations to throw a 403 "Unauthorized" status. Strangely, now, when I try to register from any IP, including the whitelisted one, I get a 503 "Service unavailable" status message.
How can I get ejabberd to allow in-channel registration from a specific IP, and that IP alone?

Answer 1

That's not how the restriction is supposed to be used. You can find an example (in .yaml) in ejabberd documentation for mod_register:
That's not how it works in ejabberd 15.x. You need three things to be able to limit registration from IP:
- ACL definition for IP.
- Access rule defining for which ACL you want to allow or deny access.
- mod_register configuration linking ip_access to your access rule.
For the (very old) 2.1.11, it is very different, but definitely does not use the all keyword for deny.
ejabberd 2.1.11 documentation show example as:
{acl, shortname, {user_glob, "??"}}.
%% The same using regexp:
%%{acl, shortname, {user_regexp, "^..?$"}}.
{access, register, [{deny, shortname},
{allow, all}]}.
{modules,
[
...
{mod_register, [{access, register},
{ip_access, [{allow, "127.0.0.0/8"},
{deny, "0.0.0.0/0"}]}
]},
...
]}.
As you see deny should match IP address blocks to deny.