NIS - byuid

[Ian Bissix]

We inadvertently ran a ypmake on a client NIS machine (which crashed part way through).

Whenever a user tried to log in they were identified as root (a whoami command returned an "Intruder Alert" message).

Did a ypwhich -m and for all entries this seemed normal except for the passwd.byuid which was now no longer pointing to the server but rather to the client.

Did a ypset and then restarted the nis.server which seemed to cure the problem but upon rebooting the server we immediately got the same issues (users identified as root) again.

Repeated the fix above (ypset etc) and once again we were working but preumeably this will just happen again if we reboot the client or the server. How can I make this mapping permanent.

many thanks

Ian

[Robert-Jan Goossens]

Hi Ian,

Check below file, your NIS settings should be

/etc/rc.config.d/namesvrs
NIS_MASTER_SERVER=0
NIS_SLAVE_SERVER=0
NIS_CLIENT=1

Regards,
Robert-Jan

[Ian Bissix]

Hi Robert-Jan

I checked these files and they are indeed different, having:

NIS_MASTER_SERVER=0
NIS_SLAVE_SERVER=1
NIS_CLIENT=1

But this seems to be consistent across all of our clients using NIS and we are not seeing this issue elsewhere.

cheers

Ian

[Robert-Jan Goossens]

and is your NIS_DOMAIN= pointing to the correct domain ?

Robert-Jan

[Ian Bissix]

Yep - looking in the namesvrs file the NIS_DOMAIN is correct.

[Robert-Jan Goossens]

Ian,

a bit strange to have "NIS_SLAVE_SERVER=1" set on a NIS client.

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Steps to setup a NIS Master Server, NIS Slaves, and NIS Clients DocId: KBAN00000276

http://www4.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000080360992
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are you sure it is only a NIS client ?

Robert-Jan

[Ian Bissix]

They do seem to be very strange settings - unfortunately this is an inherited system and so I have no idea as to why any particular settings were chosed. My concern there is that they do match all of the other clients which dont seem to have a problem.

Could they all be servers relaying data on driven by the master server? IF I look at the master server then the settings are:

NIS_MASTER_SERVER=1
NIS_SLAVE_SERVER=0
NIS_CLIENT=1

Which would seem to support that.

Equally, it was only the passwd.byuid that had the wrong (local) server when doing the ypwhich -m and I would have thought that there would be more errors there if the NIS_SERVER

[Robert-Jan Goossens]

Could you check if below file displays the correct NIS server?

/var/yp/binding//ypservers

Robert-Jan

[Ian Bissix]

That directory does not seem to exist I am afraid.

The /var/yp/binding directory is there but no other directories.

There is a file in /var/yp/binding/ called:

.2

and that is all.