netgroup idea Where to find more details

[mar_q]

Hello.

Someone could help me where to learn in details how netgroup idea works?

What I mean is not man page for netgroups or configuration itself but more details how it works.

Thanks.

[Matti_Kurkela · Accepted solution]

The "idea" of netgroups works like this:

A sysadmin can create and manage lists of users, hosts, NIS domains and/or combinations of them in a central location, and publish them with NIS. Each list defines a netgroup and has a name. There is a standard set of function calls the other programs can use to look up this information: setnetgrent(), getnetgrent(), endnetgrent() and innetgr(). This means an application must specifically support netgroups to make any use of them.

On Linux, I can remember two places where netgroups can be used, but others are likely to exist.

• In /etc/exports, you can specify a netgroup containing a list of hosts instead of manually listing each host you wish to export a filesystem to. If your environment contains a number of NFS servers and a larger group of NFS clients, you could use netgroups when configuring the exportable file systems: when you add a new client, you'd only have to update the netgroup to allow the new client to access all the file servers. Otherwise, you would have to update the configurations of each NFS server independently.
• When configuring sudo (i.e. in the sudoers file), you can use netgroups that specify lists of users or lists of hosts, wherever required in your configuration. (With newest versions of sudo, you can store the sudo configuration in LDAP, giving you a more direct and SSL-secureable way to centrally manage sudo configuration)

Was this the sort of information you wanted to know?

[mar_q]

Yes.

I accept your answer. Thanks.

One question. Do you know any doc which ilustrate it? I like it have presented like it used to be in training manuals when you're on training.