Siddharth sent in questions he got for sysadmin interview:
- Difference between layer 2 and layer 3 devices?
- What is VLAN?
- What is the subnet for a class C network?
- Are you familiar with automounter?
- Have you configured an NIS server/client?
- Have your configured a NFS server?
- Windows and Linux interoperability how to?
- What is RAID 1?
6 Comments on Interview questions for a sysadmin
Q-2 VLAN
VLAN stand for Virtual Local Area Netwok. I VLAN We break the Whole Netwok into small Segment Which helps us Controlling Broadcost Domain and Providing Authentication for Different segment by appying ACL’s. Also it helps by providing ease of Management the Network. Problems can be identified more easily
Vlan :
Vlan defines logical grouping of computers in a lan.set of ports can be assigned to every logical group.
Vlan is used to reduce the broadcast packets.
Defines to process of one subset of a switch interface as one broad cast domain.
Broadcasts are not forwarded between vlan’s.
and each port can be created as Individual vlan.
About Port Information:
system connected to port is called access ports
switch to switch port is called trunk port.
Here are the steps to configure the NFS server in this scenario:
1. Edit the /etc/exports file to allow NFS mounts of the /home directory with read/write access.
/home *(rw,sync)
2. Let NFS read the /etc/exports file for the new entry, and make /home available to the network with the exportfs command.
[root@bigboy tmp]# exportfs -a
[root@bigboy tmp]#
3. Make sure the required nfs, nfslock, and portmap daemons are both running and configured to start after the next reboot.
[root@bigboy tmp]# chkconfig nfslock on
[root@bigboy tmp]# chkconfig nfs on
[root@bigboy tmp]# chkconfig portmap on
[root@bigboy tmp]# service portmap start
Starting portmapper: [ OK ]
[root@bigboy tmp]# service nfslock start
Starting NFS statd: [ OK ]
[root@bigboy tmp]# service nfs start
Starting NFS services: [ OK ]
Starting NFS quotas: [ OK ]
Starting NFS daemon: [ OK ]
Starting NFS mountd: [ OK ]
[root@bigboy tmp]#
After configuring the NIS server, we have to configure its clients, This will be covered next.
Configuring The NFS Client
You also need to configure the NFS clients to mount their /home directories on the NFS server.
These steps archive the /home directory. In a production environment in which the /home directory would be actively used, you’d have to force the users to log off, backup the data, restore it to the NFS server, and then follow the steps below. As this is a lab environment, these prerequisites aren’t necessary.
1. Make sure the required netfs, nfslock, and portmap daemons are running and configured to start after the next reboot.
[root@smallfry tmp]# chkconfig nfslock on
[root@smallfry tmp]# chkconfig netfs on
[root@smallfry tmp]# chkconfig portmap on
[root@smallfry tmp]# service portmap start
Starting portmapper: [ OK ]
[root@smallfry tmp]# service netfs start
Mounting other filesystems: [ OK ]
[root@smallfry tmp]# service nfslock start
Starting NFS statd: [ OK ]
[root@smallfry tmp]#
2. Keep a copy of the old /home directory, and create a new directory /home on which you’ll mount the NFS server’s directory.
[root@smallfry tmp]# mv /home /home.save
[root@smallfry tmp]# mkdir /home
[root@smallfry tmp]# ll /
…
…
drwxr-xr-x 1 root root 11 Nov 16 20:22 home
drwxr-xr-x 2 root root 4096 Jan 24 2003 home.save
…
…
[root@smallfry tmp]#
3. Make sure you can mount bigboy’s /home directory on the new /home directory you just created. Unmount it once everything looks correct.
[root@smallfry tmp]# mount 192.168.1.100:/home /home/
[root@smallfry tmp]# ls /home
ftpinstall nisuser quotauser smallfry www
[root@smallfry tmp]# umount /home
[root@smallfry tmp]#
4. Start configuring autofs automounting. Edit your /etc/auto.master file to refer to file /etc/auto.home for mounting information whenever the /home directory is accessed. After five minutes, autofs unmounts the directory.
#/etc/auto.master
/home /etc/auto.home –timeout 600
5. Edit file /etc/auto.home to do the NFS mount whenever the /home directory is accessed. If the line is too long to view on your screen, you can add a \ character at the end to continue on the next line.
#/etc/auto.home
* -fstype=nfs,soft,intr,rsize=8192,wsize=8192,nosuid,tcp \
192.168.1.100:/home:&
6. Start autofs and make sure it starts after the next reboot with the chkconfig command.
[root@smallfry tmp]# chkconfig autofs on
[root@smallfry tmp]# service autofs restart
Stopping automount:[ OK ]
Starting automount:[ OK ]
[root@smallfry tmp]#
After doing this, you won’t be able to see the contents of the /home directory on bigboy as user root. This is because by default NFS activates the root squash feature, which disables this user from having privileged access to directories on remote NFS servers. You’ll be able to test this later after NIS is configured.
Note: This automounter feature doesn’t appear to function correctly in my preliminary testing of Fedora Core 3. See Chapter 29, “Remote Disk Access with NFS”, for details.
All newly added Linux users will now be assigned a home directory under the new remote /home directory. This scheme will make the users feel their home directories are local, when in reality they are automatically mounted and accessed over your network.
linux interview qns
1.How to disable usb ports in linux system.
2.How to give ftpuser permissions to one newly created user.
3.alredy mail server is there in my network,my mail user tell to my mails r not going to outside n outside mails r not comming.. how to troubleshoot it ..where u have to check????
4.wt is difference btwn NIS and NIS plus.
5.can u increse runlevls in linux? how many runlevels r there in linux kernel.If u increse runlevels how to increse??
6.U can install two different linux versions in single system.. with out Vmware?
7.wt is diff btwn scp and tcpdump
8.wt is current package version of FTP??/
3.What is the subnet for a class C network?
11111111.11111111.11111111.00000000 (255.255.255.0)
i have skills in • Networking, Systems administration
• Hardware Troubleshooting
• Good exposure in interconnecting devices and cabling
• Network planning, design and implementing using servers and workstations
i am attending interview for networking administrator what type of questions they asked plz send question&answers to my email address