[Fedora-directory-users] Installing passsync in a AD domain with multiple domain controllers?
Howard Wilkinson
howard at cohtech.com
Thu Aug 23 14:38:20 UTC 2007
Richard Megginson wrote:
> Howard Wilkinson wrote:
>> I think I have worked this out but want ot make sure I have got it
>> correct!
>>
>> Whereas the sync agreement for the FDS <-> AD is from a single FDS
>> server to a single AD domain controller the Passsync facilitiy needs
>> to be installed on all Domain Controllers (am I right?)
>>
>> The reason for this is that the password is hashed before injection
>> into the AD
> Are you sure about this? What application does the hashing? AFAIK,
> AD needs the clear text password in order to do its own specific
> hashing and encryption.
This may be terminology, AD is a collection of services running on the
Domain Controllers. One of these services is replication which processes
the transfer of strictly LDAP based information. By the time replication
gets the data therefore the password has been hashed (I am relatively
sure about this). The password change hook is called on the domain
controller that accepted the password change prior to the hash is
applied - YES??? Again I think I have this right! Therefore whichever DC
gets to take part in the password change is going to need the passsync
service.
I am looking for someone to definitively confirm or deny this premise as
I need to push this service out to multiple controllers and include it
in new builds.
>> and propagated to other DC's so it is then useless to the Passsync
>> code. The hook therefore needs to be on the DC that receives the
>> password change, which can be any DC in the environment....
> FDS must get the clear text password in order to perform its own
> hashing which is different from the way AD does hashing.
Got that, hence my concern with placement of the passsync service
>>
>> A further concern arises with a multi-master FDS and a multiple DC
>> AD. Can the system be set up with multiple FDS <-> AD sync agreements
>> and still allow the results to propagate within the FDS. This would
>> make sense from a fault-tolerant perspective, and off-hand I think
>> the replications should preserve behaviour, but can anybody spot a
>> problem?
> This gets a little tricky. In general, AD <-> FDS sync is a simple
> synchronization protocol, not a full blown multi-master replication
> protocol as FDS to FDS or AD to AD. FDS cannot be a full replication
> peer with AD. However, samba4 is getting closer and closer . . .
But if I have 2 FDS servers running in multi-master and they both have
synchronisation agreements with a single DC will they fight each other,
and can they fight the DC's - deletes are the obvious problem. The ideal
topology would have each of a multi-master set of FDS talking to more
than one DC each allowing any system to fail and the services carrying
providing up to date functionality.
Samba4 is something I would love to have but it looks a long way off as
far as a replacement for what we have today... :-(
Another thing about multi-master FDS's is which FDS should a DC talk to
for its passsync updates? Ideally each DC would pick a different FDS or
more than one if the first failed. .... Fault tolerance is fun...
>> --
>>
>> Howard Wilkinson
>>
>>
>>
>> Phone:
>>
>>
>>
>> +44(20)76907075
>>
>> Coherent Technology Limited
>>
>>
>>
>> Fax:
>>
>>
>>
>>
>>
>> 23 Northampton Square,
>>
>>
>>
>> Mobile:
>>
>>
>>
>> +44(7980)639379
>>
>> United Kingdom, EC1V 0HL
>>
>>
>>
>> Email:
>>
>>
>>
>> howard at cohtech.com
>>
>>
>>
>> ------------------------------------------------------------------------
>>
>> --
>> Fedora-directory-users mailing list
>> Fedora-directory-users at redhat.com
>> https://www.redhat.com/mailman/listinfo/fedora-directory-users
>>
>
> ------------------------------------------------------------------------
>
> --
> Fedora-directory-users mailing list
> Fedora-directory-users at redhat.com
> https://www.redhat.com/mailman/listinfo/fedora-directory-users
>
--
Howard Wilkinson
Phone:
+44(20)76907075
Coherent Technology Limited
Fax:
23 Northampton Square,
Mobile:
+44(7980)639379
United Kingdom, EC1V 0HL
Email:
howard at cohtech.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/fedora-directory-users/attachments/20070823/52598939/attachment.htm>
More information about the Fedora-directory-users
mailing list