How to specify LDAP authentication details with dirmngr/GnuPG 2.1?

[Philip Colmer]

I'm trying to use GnuPG 2.1 and using an LDAP server as the keyserver.

>From what I can tell, the keyserver configuration has moved from gpg
to dirmngr but I am really struggling to figure out how I should be
configuring GnuPG/dirmngr so that it knows how to authenticate with
the LDAP server.

I'm editing the dirmngr.conf file but I cannot come up with a
combination of settings that not only specifies the LDAP server as the
keyserver (that's the easy bit) but also specifies the username and
password to use with it.

I've tried separating with colons, I've tried using something like:

ldap://<username>:password at server

I've tried:

keyserver ldap://server binddn="username" bindpw=password

Does anyone know the correct way to specify a username and password
for use with an LDAP keyserver, please?

Thanks.

Philip