On pe, 18 loka 2019, Pieter Baele wrote:
All Windows clients are properly enrolled into the AD domain.
We can't use two-way trust because of reasons you explained here before. A
one-way external trust is used. All perfectly established and working, but
somehow windows clients don't follow the topology.
Ok, so this is the key
information you did not say in the original
External trust only works for the domain you trust directly, not for
anything else. Remember that in Active Directory each DNS domain is
considered a separate AD domain unless it is marked as top level name
route in forest trust information. As far as I understand, the routing
does not apply to externally trusted domains. At least,
explicitly claims it in the table comparing external and forests trusts:
"Since it is an external trust, the cross-forest targets only cover the
domains that have direct trusts. Only these DCs should be used to target
Kerberos requests or Kerberos Forest Searches."
and just before that there is a generic explanation how the information
about trust is stored -- note that for forest trust there is topology
information (forest trust information attribute):
External trusts are used to enable trusts between two domains that are
in different forests. A forest trust is similar to an external trust
between the root domains of both forests, but it takes the trust one
step further to encompass all of the domains. The basic trust
information (for both external trust and forest trust) is represented by
a trusted domain object (TDO). The TDO for an external trust contains
the name of the other domain with which the trust is established, its
domain security identifier (SID), the trust direction, the type of
trust, and some other attributes.
When there is a forest trust, the trust is marked as "Forest." The TDO
also contains an additional Forest Trust Information attribute. The
Forest Trust Information attribute contains information about all of the
domains in the remote forest, the tree names, and any alternate name
suffixes. This information is used to route authentication and lookups
to the remote forest when needed. This information is propagated to the
global catalogs so that any domain controller can look it up. The TDOs
are stored in the Domain container that is in Active Directory.
The tree names and alternate name suffixes are stored in TopLevelName
(or TLN) records. The DNS name, network basic input/output system
(NetBIOS) name, and SID for every domain is stored in DomainInfo
records. Because of this, the forest trust contains enough information
to reasonably determine which services or users can reside in the other
By adding a domain_realm mapping to a windows client, also describe
FreeIPA-users before, the routing problem is solved. But I (and especially
the AD admins ;-) ) would prefer to solve the underlying issue.
external trust, use forest trust. The effect you see is a
design limit of external trust.
Thanks a lot, it is quite hard to find experts (with knowledge of
LDAP, AD and different Kerberos implementations)(we are reaching out to RH)
are reaching out to Red Hat support, your request will eventually
get to my hands.
/ Alexander Bokovoy
Sr. Principal Software Engineer
Security / Identity Management Engineering
Red Hat Limited, Finland