Friday, 22 August 2014

DHCP SERVER INTERVIEW QUESTIOTON



DHCP SERVER INTERVIEW QUESTIOTON
           1)     What is DHCP?
o   DHCP stands for "Dynamic Host Configuration Protocol". DHCP allows for dynamic allocation of network addresses and configurations newly attached hosts.

2)      Describe how the DHCP lease is obtained.
o   It’s a four-step process consisting of (a) DHCP Discover, (b) DHCP Offer, © DHCP Request (d) DHCP Acknowledgement.
3)      Can a BOOTP client boot from a DHCP server?
o   Only if the DHCP server is specifically written to also handle BOOTP queries.
4)      What is DHCP Scope?
o   Scope - A range of IP addresses that the DHCP server can assign to clients that are on one subnet.
5)      What is Supersocpe?
o   Superscope is a range of IP addresses that span several subnets. The DHCP server can assign these addresses to clients that are on several subnets.
6)      What is Client Reservation?
o   Client Reservation is used to be sure a computer gets the same IP address all the time. Therefore since DHCP IP address assignments use MAC addresses to control assignments.
7)      What is Exclusion range?
o   Exclusion range is used to reserve a bank of IP addresses so computers with static IP addresses, such as servers may use the assigned addresses in this range. These addresses are not assigned by the DHCP server.
8)      Which utility is used to compact DHCP Database?
o   JETPACK
9)      What is Scope Options?
o   Scope options are IP configuration settings for a particular subnet including the IP address of the router (default gateway), DNS Server, Domain Name, WINS Server etc.
10)    Why we need DHCP Relay Agent?
o   When you have clients on different Subnets, you either need to have multiple DHCP Servers, or a DHCP Relay Agent. All DHCP packets are broadcast packets. When there is a DHCP broadcast the router will not forward the broadcast packets. To allocate IP address for the clients which are on a network other than DHCP server, you need to configure DHCP relay agent on Router. The DHCP Relay Agent allows you to place DHCP Clients and DHCP Servers on different networks.
o   I can’t seem to access to the corporate network and on ipconfig my address is 169.254.X.X. What happened?
o   The 169.254.x.x netmask is assigned to Windows machines running 98/2000/XP if the DHCP server is not available. The name for the technology is APIPA (Automatic Private Internet Protocol Addressing)
11)      We’ve installed a new Windows-based DHCP server, however,           the  users do not seem to  be getting DHCP lease for the Server. Reason out why the lease is not    available?
          The server must be authorized first with the Active Directory.
       How can you force the client to give up the dhcp lease if you have     access to the client  PC?
o   ipconfig /release
12)    What authentication options do Windows 2003 Servers have for remote clients?
o   PAP, SPAP, CHAP, MS-CHAP, MS-CHAP v2 and EAP.

13)What is DHCP ?

 DHCP is used to automatically provide IP address to client computers.


 14)Explain DHCP 4 packets.

  • Discover = client sends request for IP.
  • Offer = DHCP server send and Offer with IP address.
  • Request = if clients accepts the IP it sends a request to DHCP.
  • Ack = DHCP server sends ack for the same.
15)What is client reservation in DHCP ?
         to reserver a specific IP for a specific machine or host.

16)What is WINS ?
          It is used to resovle NetBIOS Computer name to IP address.

17)How DHCP Works
  • DHCP uses a four-phase process to configure a DHCP client as given below
  • IP lease discover : When client initializes it broadcasts a request to find the DHCP server to
  • get a IP address from available DHCP server.
  • IP lease offer : All DHCP servers that have valid IP addressing information available send an
  • offer to the client request.
  • IP lease request : The client selects the IP addressing information from the first offer it
  • receives and broadcasts a message requesting to lease the IP addressing information in the offer.
  • IP lease acknowledgment : The DHCP server that made the offer responds to the message,
  • and all other DHCP servers withdraw their offers. The IP addressing information is assigned to
  • the client and an acknowledgment is sent

18)Ipconfig Switches/Options
/all : Produces a detailed configuration report for all interfaces
/flushdns : Removes all entries from the DNS name cache
/registerdns : The DNS domain name for client resolutions
/displaydns : Displays the contents of the DNS resolver cache
/release <adapter> : Releases the IP address for a specified inter
Ø  HCP Relay Agent
  • A relay agent is a small program that relays DHCP/BOOTP messages between clients and
  • servers on different subnets. The DHCP Relay Agent component provided with the Windows
  • 2000 router is a BOOTP relay agent that relays DHCP messages between DHCP clients and
  • DHCP servers on different IP networks. For each IP network segment that contains DHCP
  • clients, either a DHCP server or a computer acting as a DHCP relay agent is required.

19)To add the DHCP Relay Agent
                                         i.    Click Start, point to Programs, point to Administrative Tools, and then click Routing And
Remote Access.
                                        ii.    In the console tree, click Server name - IP Routing - General.
                                       iii.    Right-click General, then click New Routing Protocol.
                                      iv.    In the Select Routing Protocol dialog box, click DHCP Relay Agent, then click OK.
20)What is DHCP.
DHCP is a protocol which is designe for Automatic Give the IP Address to DHCP client..
DHCP Assine the IP Address for few days Lease & capture the clients MAC address..
It is Updated version of BootP…
DHCP is used for MAC address to IP mapping its support both static and dynamic mapping.Static mapping are done just like bootstrap and for dynamic mapping it have database of MAC and IP when a packet with a MAC comes ask for ip its check that assigne a dynamic IP fixed that for a specific time and then return that packet with that IP

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