https://bugs.openldap.org/show_bug.cgi?id=10029
--- Comment #3 from Ondřej Kuzník ondra@mistotebe.net --- You won't risk running into port no. exhaustion except in small environments - even though the local part of the 4-tuple is fixed, the remote part gives you unlimited number of source ports if you have enough source addresses. Yes, cn=monitor will struggle, we've seen that, but that's a design choice of slapd's own making.
We might have to add a configuration option (and a sane default) if we get a nonsensical (especially negative) max number.