5.3.3. Edit the /var/yp/securenets File

5.3.3. Edit the /var/yp/securenets File

NIS listens to all networks, if the /var/yp/securenets file is blank or does not exist (as is the case after a default installation). One of the first things to do is to put netmask/network pairs in the file so that ypserv only responds to requests from the proper network.

Below is a sample entry from a /var/yp/securenets file: 

         255.255.255.0 192.168.0.0

Warning

Never start an NIS server for the first time without creating the /var/yp/securenets file.

This technique does not provide protection from an IP spoofing attack, but it does at least place limits on what networks the NIS server services.


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