NIS question 2

[sm42]

Hello

I have used NIS in a few environments and set-up nis clients.

How does NIS determine which map to use, when a client requests?
maybe a system call??
how does NIS know whether to user hosts map or the ethers map ?

thanks

 

[djr111]

isn't it the /etc/nsswitch.conf.

cp /etc/nsswitch.nis /etc/nsswitch.conf

If you have in the /etc/nsswitch.conf something like this, then it will use nis first since it is stated first, if nis fails it should attempt to use local files.

passwd: nis files
group: nis files


that is if I understand your question correctly...

 

[sm42]

nsswitch.conf is NOT what I'm looking for

that's the order in which place to resolve name services

How does NIS know which NIS maps to use?
there can be say more than 15 NIS maps, how does NIS know which map to consult in order to get the answer


thanks

 

[AnotherAlan]

Second link in google;

http://www.softpanorama.org/Net/NIS/minitutorial.shtml

Did you try and look for this info yourself??

 

[sm42]

seen that article and have googled to no success

 

[AnotherAlan]

Then I don't understand the question, because the article states that the ypserv daemon handles client requests for nis maps.
It also states that nicknames are used to describe actual references to nis maps, ypcat -x tells you this.

As an example `ypmatch <user> passwd`, tells nis to look in the passwd map, which is a nickname for passwd.byname.

 

[sm42]

agreed, with regards to your example
and that ypserv handles NIS requests

how about when you dont tell NIS which maps to use
e.g ssh host1
or
NIS will look at hosts and netgroups
but how does NIS know this ?

 

[sm42]

aplogies if I caused any confusion

 

[GunnarD]

Well if a program is asking for an ip-adress then the system are using gethostbyname() and that function knows that it should use hosts maps.

And for example when you using passwd to change/set password for a user, the program use getpwname()/setpwnam() function and these functions knows att it should use passwd maps.

The same for the rest of the maps, the functions in the system knows what maps to ask for.

 

[sm42]

gunnard,
thanks for that,that will do, the system call should determine which nis map nis will use


nice one