Basic Networking Questions & Answers for Interview

What is Full form of ADS?

Active Directory Service

How will you register and activate windows?

to initiate activation click on the windows Activation icon in the system tray. Once you have activated windows XP, this icon disappears from the system tray. 
For registration 
Start ==> Run ==> regwiz /r

Where do we use cross and standard cable?

Computer to computer ==> cross 
Switch/hub to switch/hub ==>cross 
Computer to switch/hub ==>standard

How many pins do Router serial ports have?

60 pins.

How will you make partition after installing windows?

My computer ==> right click ==> manage ==> disk management ==> 
select free space ==> right click ==> New partition

What is IP Address?

IP address is a 32 bit Logical Address defined in Network Header.

What is Private IP Address?

IANA has reserved Three classes for private address If you do decide to implement a private IP address range, you can use IP addresses from any of the following classes: 
Class A      10.0.0.0    10.255.255.255 
Class B       172.16.0.0     172.31.255.255 
Class C       192.168.0.0     192.168.255.255

What is public IP address?

A public IP address is an address leased from an ISP that allows direct Internet communication.

What’s the benefit of subnetting?

Dividing large Subnets(Network) into small small subnets(Networks) is called subnetting.

What are the differences between static ip addressing and dynamic ip addressing?

With static IP addressing, a computer (or other device) is configured to always use the same IP address. With dynamic addressing, the IP address can change periodically and is managed by a centralized network service

What is APIPA?

Automatic private IP addressing (APIPA) is a feature. DHCP clients use this IP range when they don’t get IP lease from available DHCP Server. The range of these IP address are the 169.254.0.1 to 169.254.255.254 with a default Class B subnet mask of 255.255.0.0.

What are the LMHOSTS files?

The LMHOSTS file is a static method of resolving NetBIOS names to IP addresses in the same way that the HOSTS file is a static method of resolving domain names into IP addresses. An LMHOSTS file is a text file that maps NetBIOS names to IP addresses; it must be manually configured and updated.

What is DHCP scope?

A scope is a range, or pool, of IP addresses that can be leased to DHCP clients on a given subnet.

What is FQDN?

An FQDN contains (fully qualified domain name) both the hostname and a domain name. It uniquely identifies a host within a DNS hierarchy

What is the DNS forwarder?

DNS servers often must communicate with DNS servers outside of the local network. A forwarder is an entry that is used when a DNS server receives DNS queries that it cannot resolve locally. It then forwards those requests to external DNS servers for resolution.

Which command will you use to find out the name of the pc in networks?

NSLOOKUP [192.168.0.1] 
[Ip of target computer]

How will enable sound service in 2003?

By default this service remain disable to enable this service
Start ==> administrative tools ==> service ==> windows audio ==> start up type ==> automatic

Wireless Router & it's common Problems

What is a Wireless Router?

As the name suggests, a wireless router is basically a routing device, i.e. it manages the forwarding and accepting of data packets. There is a radio transmitter and receiver which sends and receives modulated radio signals. A circuit converts electronic signals in to radio signals and a complementary circuit converts radio to electronic signal.

As the wireless router packs and uses several technologies, almost simultaneously, many wireless router problems are likely to crop up. Let us move on to see what are the problems with wireless router and how to troubleshoot them.

• The Adapter or Network is not Listed: This is one common type of wireless router setup problems encountered when you've just set up a connection. This may be due to problems with the related to the card slot or the USB adapter in the PC. Remove and reconnect the adapter should help on most occasions. If not, using a Device Manager, try to uninstall or reinstall the adapter. In case the adapter is being shown in the available networks list, but connection cannot be established, update or reinstall the driver using the Properties panel. Also, check some obvious negligence by verifying if the client's wireless adapter status is "Enabled."
• Router Name does not Appear: If the router's name does not appear, enable "SSID broadcasts" on the router setting. Or else, manually enter the network's name to the client's Preferred Connections list. Be sure to exactly match the router's, as it is case-sensitive.
• Adapter Status shows "Not Connected": If the adapter status shows "Not Connected," go to View Available Networks and click Connect after selecting a wireless network. Some wireless router installation problems need router reconfiguring. If the network's name you wish to connect does not appear in this list or you are unable to connect, try to re-configure the router to server connection using the configuration manual of your router. Read more on how to connect a wireless router.
• Try to Ping: Pinging is a method of sending a message to another computer on the network, to see if it is reachable or not. Go to the command prompt and type 'ping' followed by the IP address of the machine you wish to check. This way you can ensure proper connectivity of a machine using another computer which you know has reliable connectivity.
• Pinging Failed: If pinging of the router fails, it might be a problem specific to wireless devices. Using the admin utility of the router, view Wireless LAN settings and match them with the wireless connection settings of the client. Both, router and client, must be 802.11 standard compatible. If the client machine is 802.11b, the router must be 11b, g, or n and you must enable b+g protection on the 11g router. In case of a 802.11a client, it is a must to use 11a router. In case of dual-band router, both ends may be configured to use 11b/g, a, or both.
• Connection Speed is too Slow: Wireless router speed problems are the most commonly reported complaints. The main reason can be interference, as routers work in the 2.5GHz band, which are also used by microwaves, wireless phones, garage door remote controllers, and some other wireless devices. Try turning these off and there would surely be an improvement.
• Forgot Password: Uh oh! You're in trouble! Ha, just kidding. It's quite simple to get out of the mess. A reset button is provided in the back of the router case. It is just a small hole in which you can insert a pin tip and keep the reset button pressed for about 3 to 5 seconds. But now, all the settings are set back to their default factory settings. By resetting the configuration, you can do away with wireless router security problems.
• Cold Spots: There may be areas, sufficiently within the range of the router, but the signal strength in these area might not be present. The main reason for such problems with wireless routers is due to its placement. Many times, the signals get reflected from walls, floors or other obstructing objects. The best way to nullify this problem is by using a 802.11n router and adapter, which uses a MIMO (Multiple Input Multiple Output) technology. Such a MIMO-enabled router will take all the reflected signals and compares them to fill the voids so as to join together and complete all possible signal.

The best way to minimize any wireless router problem is to verify the physical connectivity of the router and the adapter. Most wireless router connection problems crop up due to improper plugging of the Ethernet or WAN cables. Check the router's WAN connection with the cable/DSL modem and Ethernet links to the client. Swapping of cables will help single out damaged LAN cable, if any.

Router Vs Switch

Router Vs Switch
Here are some points of comparison which highlight the differences between a router and a switch.

Router	Switch
Basically, a router is used to connect computers belonging to one network with those belonging to another or other networks. Thus, a router connects two or more different networks.	A switch on the other hand, connects different computers within one network.
As per the OSI model, a router is a Network Layer device, i.e. it operates at Layer 3.	Unless it is a multi-layer switch, a network switch operates at Layer 2 (Data Link Layer).
Routers are much more sophisticated and intelligent network devices, as compared to switches.	In comparison with routers, switches are less sophisticated and less intelligent.
A router works on the principle of IP addresses.	A switch works on the basis of MAC addresses.
A router's inbuilt hardware makes use of routing algorithms to compute the best possible path for routing data packets across different computer networks.	A switch does not perform any such activities.
Routers have their own inbuilt operating systems and they need to be configured before use.	Most switches do not require any prior configuration and are usually 'ready-to-use'.

Switch Vs Hub

Switch Vs Hub
Here is a tabular representation of the differences between a switch and a hub.

Switch	Hub
As per the OSI model, network switches are classified as Data Link Layer devices, i.e. they operate at Layer 2. However, certain multi-layer switches can operate at higher layers as well.	As per the OSI model, a hub is a Physical Layer device, i.e. it operates at Layer 1.
A switch is a more sophisticated network device and is more expensive than a hub.	A hub is a very primitive device and is comparatively much cheaper.
A switch is an intelligent device, it transmits the data packets from the source computer to only those network computers to which the data packets are originally intended.	A hub is a 'dumb' device to say the least. It broadcasts the data packets to each and every networked computer, and not just the target computer or set of computers to which the data packets were originally intended to be sent.
There is optimum utilization of network bandwidth in case of switches, and bandwidth wastage is minimal.	Due to their broadcast mechanism of data transmission, there is unnecessary wastage of network bandwidth which results in slow operation and data transfer speeds.
Switches are full-duplex devices, i.e. both, data transmission and reception can take place simultaneously.	Hubs are half-duplex devices, i.e. both, data transmission and reception cannot take place simultaneously.
Network security is much better with the use of a switch, as compared to a hub.	Thanks to its broadcast mechanism, network security becomes a big issue and a loophole in the case of a hub.

The Most Commom Remote Desktop Error in Windows

Error :The remote computer disconnected the session because of an error in licensing protocol.

To resolve this problem, follow these steps:

1. On the computer that cannot open the Remote Desktop session, click Start, click Run, type cmd, and then click OK.
2. At the command prompt, type the following command, and then press ENTER:
   NET START TERMSERVICE
3. Click Start, click Run, type regedit, and then click OK.
4. In Registry Editor, locate and then click the following key:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensing
5. Delete all the keys that are located under the
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensing
   key.
6. On the File menu, click Exit.
7. Restart the computer.