SUMMARY: netid ypmap

From: Walter Hartheimer (walter@hp715.bear.com)
Date: Tue Sep 21 1993 - 08:17:29 CDT


Original messages:

------------------------------------------------------------------

We would like to change our NIS master to a non Sun machine.

A problem we have is that the map 'netid.byname' does
not seem to have a corresp. source and it is generated
by a binary called $(YPDIR)/mknetid.

An excerpt looks like:

unix.wash_dc_site@bears 0:wash_dc_site
unix.fast1_fisbb@bears 0:fast1_fisbb
unix.vaxj08@bears 0:vaxj08
unix.vaxj01@bears 0:vaxj01
unix.ibmtst@bears 0:ibmtst

Has anyone reverse engineered this map?

What is it used for?

------------------------------------------------------------------

Message 12/132 from Rich Schultz Sep 14 '93 at 6:30 pm

Return-Path: <ccrwest.org!rich>

netid is used to make some things faster, for example, assigning a
user's group membership at login. You can run just fine without it, and
we do on some of our nets.

Rich Schultz
rich@ccrwest.org

------------------------------------------------------------------

Message 15/132 from Thomas Dwyer III Sep 14 '93 at 9:44 am

Return-Path: <mtu.edu!tomiii>

On a Sun, the map looks like this:

bambam(338)% ypcat -k netid.byname
unix.bambam.cts.mtu.edu@toontown 0:bambam.cts.mtu.edu
unix.localhost@toontown 0:localhost
unix.mtu.edu@toontown 0:mtu.edu
unix.13120@toontown 13120:400
unix.9876@toontown 9876:10
unix.8888@toontown 8888:10
unix.7122@toontown 7122:30
unix.5880@toontown 5880:10,5,35,87,7662
unix.5773@toontown 5773:10
unix.2666@toontown 2666:400
unix.2041@toontown 2041:10
unix.1926@toontown 1926:10
unix.1640@toontown 1640:50
unix.1391@toontown 1391:50
unix.1030@toontown 1030:10
unix.11@toontown 11:10
unix.10@toontown 10:10
bambam(339)%

The key is made up of the OS type (unix) and something which makes this
key unique per user (the UID). Just in case there are two "unix" systems
on the network with the same UID, "@domain_name" is appended to the key.
The datum is made up of UID:primary_group:other_group:other_group:...

The map is used to determine what groups a user belong to. It would seem
this is redundant, as the /etc/group file contains the master list of
who is in what group, however you will find that your group permissions
fail if netid is corrupt or missing. I suspect the netid map is just
a quick compilation of /etc/group and /etc/passwd to speed up the process
of determining your process credentials.

Does this help?

Cheers,
Tom.III
byte 2105
Walter Hartheimer | Bear Stearns & Co. Inc.
Email: walter@bear.com | 245 Park Avenue, Fifth Floor
Voice: 1+212-272-9382 | New York, NY 10167
Fax: 1+212-272-5850 |



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:08:16 CDT