[Samba] nsupdate failed: GSSAPI error: A token had an invalid message integrity check

Michael Jones samba at jonesmz.com
Fri Jan 28 22:45:54 UTC 2022

Thank you for the help

On Fri, Jan 28, 2022 at 4:20 PM Rowland Penny via samba <
samba at lists.samba.org> wrote:

> On Fri, 2022-01-28 at 15:57 -0600, Michael Jones wrote:
> You need to find out which you are using, Heimdal or MIT.

It's using the version bundled with samba.  I've never attempted to
override that, so it's always been whatever version is bundled with each
samba release, since the DC was first installed. If that's Heimdal, then
it's always been Heimdal.

Samba has been using the builtin Heimdal since Samba 4 was released,
> though there is also an experimental version that uses MIT (this
> version should not be used in production).

That's fine. I don't have samba configured to use MIT, and never have.

Yet I've had the problem I'm asking for help with both before and after my
bind-tools package was switched by my package manager from the system's
heimdal to the system's mit-krb5.

Note that bind-tools using the mit-krb5 package *does not* mean that samba
ever has.

Regardless, I do agree with you that using MIT is not the right thing to
do, and am waiting on the DC to install Heimdal as I write this.

However, it doesn't seem like this has anything to do with the problem in
my original email.

We do not write your smb.conf, all we can do is to point out any
> errors

> The problem with that idea, is what may be wrong in one smb.conf, is
> perfectly valid in another. To get something to parse the smb.conf
> based on what the server role is, would probably have to be extremely
> large and entail some form of AI and mind reading capabilities :-)
> Rowland

The configuration lines were added when I experienced a problem. The
problem went away when the config lines were added (repeat per config line,
generally speaking).
Either the configuration lines are errors enough that they shouldn't be
allowed in the role that this instance of samba is running as, or they
aren't errors.

Typically I have to find out why something stopped working when I upgrade
samba, and find that the new version either stops doing something I want,
or starts doing something I don't want. The lack of consistency with the
behavior each release is the ultimate driver behind why there are hundreds
of guides telling people to add configuration lines that the mailing list
considers major problems, and why the few people who have run into a
problem they couldn't solve and therefore email the mailing list so
frequently have configurations that you think are set up incorrectly.

Compound that with the Samba software's logs having a predisposition to say
an error occurred, but give no real information about what the error was,
what might have caused it, how to fix it, or really anything. This leads to
people who may not be experts at samba, but are experts at computer admin,
finding their own solutions that only work by accident, further compounding
the problem of bad configuration files. I'm a software engineer for my day
job, so I have my own share of people "holding it wrong", and sympathize.
It's not an easy problem, but it is one that I've mitigated by having my
log messages lean toward over-explaining, even to the point of
condescension for particularly difficult situations.

Really, what I want is a single git repository that represents the
configuration for all of my samba machines, with common configuration
settings specified in smb.conf, and per machine settings specified in
appropriately named config files, and I had that working for over a year,
and it broke upon upgrade to some samba version, i don't recall which. So
this DC has config lines left over from when it shared the same git
repository as all my member machines. If it hasn't caused a problem until
now, i've generally left it alone.

Regardless, I appreciate your feedback on my configuration, and I'll take
it under advisement. Thank you.

However, I don't believe that the settings you omitted from my smb.conf are
related to nsupdate encountering the error: "GSSAPI error: A token had an
invalid message integrity check", are they? Or is there some influence
between, e.g. "winbind ..." settings and the DNS updater mechanism that I'm
not understanding?

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