system administrator interview question with answers- Part 1

1. Can a workstation computer be configured to browse the Internet and yet NOT have a default gateway?
If we are using public ip address, we can browse the internet. If it is having an intranet address a gateway is needed as a router or firewall to communicate with internet.
2. What is CIDR?
CIDR (Classless Inter-Domain Routing, sometimes known as supernetting) is a way to allocate and specify the Internet addresses used in inter-domain routing more flexibly than with the original system of Internet Protocol (IP) address classes. As a result, the number of available Internet addresses has been greatly increased. CIDR is now the routing system used by virtually all gateway hosts on the Internet’s backbone network. The Internet’s regulating authorities now expect every Internet service provider (ISP) to use it for routing.
3. What is DHCP? What are the benefits and drawbacks of using it?
DHCP is Dynamic Host Configuration Protocol. In a networked environment it is a method to assign an ‘address’ to a computer when it boots up.
Advantages
All the IP configuration information gets automatically configured for your client machine by the DHCP server.
If you move your client machine to a different subnet, the client will send out its discover message at boot time and work as usual. However, when you first boot up there you will not be able to get back the IP address you had at your previous location regardless of how little time has passed.
Disadvantage
Your machine name does not change when you get a new IP address. The DNS (Domain Name System) name is associated with your IP address and therefore does change. This only presents a problem if other clients try to access your machine by its DNS name.
4. How do you manually create SRV records in DNS?
To create SRV records in DNS do below steps: -
Open DNS
Click on Zone —– Select domain abc.local ——-
Right Click to domain and go to Other New Records——
And choose service location (SRV)
5. Name 3 benefits of using AD-integrated zones?
Benefits as follows
a. you can give easy name resolution to ur clients.
b. By creating AD- integrated zone you can also trace hacker and spammer by creating reverse zone.
c. AD integrated zoned all for incremental zone transfers which on transfer changes and not the entire zone. This reduces zone transfer traffic.
d. AD Integrated zones suport both secure and dmanic updates.
e. AD integrated zones are stored as part of the active directory and support domain-wide or forest-wide replication through application pertitions in AD.
6. How do I clear the DNS cache on the DNS server?
Go to cmd prompt and type “ipconfig/flushdns” without quotes
7. What is NAT?
NAT (Network Address Translation) is a technique for preserving scarce Internet IP addresses. For more details go to Microsoft link
8. How do you configure NAT on Windows 2003?
For above answer go to below link
Configure NAT
9. How to configure special ports to allow inbound connections?
a. Click Start, Administrative Tools, and then click Routing and Remote Access to open the Routing and Remote Access management console.
b. Locate the interface that you want to configure.
c. Right-click the interface and then select Properties from the shortcut menu.
d. Click the Special Ports tab.
e. Under Protocol, select TCP or UDP and then click the Add button.
f. Enter the port number of the incoming traffic in Incoming Port.
g. Select On This Address Pool Entry, and provide the public IP address of the incoming traffic.
h. Enter the port number of the private network resource in Outgoing Port.
i. Enter the private network resource’s private IP address in Private Address.
j. Click OK.