What can you tell me about the OSI Reference Model?
The OSI Reference Model provides a framework for discussing network design and operations. It groups communication functions into 7 logical layers, each one building on the next.
2.1Layer 1: Physical Layer
2.2Layer 2: Data Link Layer
2.3Layer 3: Network Layer
2.4Layer 4: Transport Layer
2.5Layer 5: Session Layer
2.6Layer 6: Presentation Layer
2.7Layer 7: Application Layer
What are the Linux run levels, and what is each used for?
0 Runlevel 0 Halt the system.
1 Runlevel 1 Single-user mode (for special administration).
2 Runlevel 2 Local Multiuser with Networking
3 Runlevel 3 Full Multiuser with Networking
4 Runlevel 4 null
5 Runlevel 5 Full Multiuser with Networking and X Windows
6 Runlevel 6 Reboot
What is the difference between CentOS and RedHat?
Community supported and managed versus Redhat's paid support. Free vs. Pay to play
What are the major differences between RedHat and Debian distributions?
Redhat is again a non free distribution but it favors stability over the various features of the debian distribution, which seeks to be a one stop shop for most linux users.
What configuration files would you modify to configure a linux system to authenticate against NIS?
/etc/passwd, /etc/shadow, /etc/groups, /etc/hosts, /etc/services, /etc/networks, /etc/rpc, /etc/protocols
What configuration files would you modify to configure a linux system to authenticate against AD?
Samba and LDAP, PAM confs and sssd.conf
What configuration changes would be necessary to setup a system to NFS mount a volume on startup?
Setup your fstab and mtabs to indicate the mount points, setup the network device for NFS traffic, bind a directory on the local machine to the remote using mount --bind, add the info to your /etc/idmapd.conf alter your init scripts to mount the volume on startup or set it in your crontabs
What configuration files would you modify to configure a linux system to auto-mount an NFS volume for home directories?