What is a zone?
A database of records is called a zone.
Also called a zone of authority, a subset of the Domain Name System (DNS) namespace that is managed by a name server.
What is an iterative query?
The query that has been sent to the DNS server from a Client is called iterative query.
(i. e., iterative query is nothing but give the answer for my question, don’t ask to contact that person or this person or don’t say some thing else. Simply just answer to my question. That’s all)
What is Recursive query?
Now your DNS server requests the root level DNS server for specific IP address. Now DNS server says that I don’t know but I can give the address other person who can help you in finding IP address.
What Type of Records do you find in DNS database?
Mail Exchange Record (MX record)
Go to registry èHkey_local_machineè systemècontolset001è controlèproductoptions
In that change product type from “lanmanNt” to “serverNt”
Go to Registry then search for lanmanNt then change it as serverNt
Is there any possibility to have two Primary DNS zones?
No, you should not have two primary DNS zones. Why because if u have two primary DNS zones some clients contacts first one, some clients contacts second one according to their configuration in TCP/IP properties. Then you will get problems. Actually Primary DNS zone means Single master. i.e., master is only one that is only one primary DNS zone. But you can have as many as Secondary zones.
To overcome from above problem (i.e., single master problem) in Windows 2000 we have Active Directory Integrated zones, which are multi masters.
How to create a Secondary DNS zone?
To create a secondary zone you should have Primary DNS zone or Active Directory Integrated DNS zone.
You have to follow the same procedure as same as primary DNS configuration.
But at the time selection, select Secondary zone instead of primary zone. After that it asks the primary DNS zone address provide that address.
Create forward lookup zone and reverse lookup zone as usual.
Right click on forward lookup zone èNew zoneè
Active Directory Integrated
Select Secondary zone
(Note:-The option Active Directory Integrated Zone is available on when you have installed the Active Directory; if you have not installed Active Directory the option is disabled.)
Then it asks for Primary DNS zone details, provide those details then click on finish.
Now go to Primary or Active Directory integrated zone then right click on zone name è properties èclick on zone transfer Tabè
Select allow zone Transfers
Here you can see three options.
To any server
Only to servers listed on the Name servers tab
Only to the following servers
Select anyone and give the details of secondary zone (only in case of second and third option).
Click on apply, then OK
Note: In zone transfers tab you can find another option Notify, this is to automatically notify secondary severs when the zone changes. Here also you can select appropriate options.
Note: In secondary zone you cannot modify any information. Every one has read only permission.
Whenever Primary DNS is in down click on “change” tab on general tab of properties, to change as primary, then it acts as primary, there you can write permission also.
What is the default time setting in primary zone to refresh, Retry, Expire intervals for secondary zone?
The default settings are
To Refresh interval10 minutes
To Retry interval,15 minutes
To Expire after1 day
Suppose the Secondary zone is Expired then, how to solve the problem?
First go to primary zone check primary zone is working or not.
IF primary zone is working then go to secondary zone, Right click on zone name select the “Transfer from Master” then it automatically contacts the primary DNS, if any updates are there then it takes the updates from the Primary.
How to know whether the recent changes in Primary are updated to secondary zone or not?
Compare the Serial Number on Start of Authority tab in both secondary on primary DNS zone properties.
If both are same then recent updates are made to secondary zone.
If not (i.e., secondary is less then primary) click on “Transfer from Master”
How to change form Primary to Secondary or Secondary to primary or Active directory integrated to secondary or primary like that (simply one type of zone to another type of zone)?
Go to the properties of the zone click on general tab, there you can find the option called “Change” click on it then select appropriate option.
Then click on OK
Go to properties of a zoneè click on General tab èclick on Pause button.
What system is used before DNS to resolve this host names?
How to know whether a DNS name is exist or not in the internet?
The query that has been sent to my DNS server from my computer.
The query that has been sent to other DNS servers to know the IP address of a particular server from my DNS server.
When you install a Windows 2000 DNS server, you immediately get all of the records of root DNS servers. So every windows 2000 DNS server installed on Internet has pre configured with the address of root DNS servers. So every single DNS server in the Internet can get root servers.
First and foremost has to support SRV records(SRV record identifies a particular service in a particular computer) (in windows 2000 we use SRV records to identify Domain controllers, identifying Global Catalogue, etc.
Second and third are not requirements but recommended.
Second is Dynamic Updates
Third one is IXFR (Incremental Zone Transfer)
Note: Most DNS servers support AXFR (i.e., Entire zone transfer)
In incremental we transfer only changes, but in AXFR we transfer whole.
How does DNS server know the root domain server addresses?
Every DNS server that has installed on Internet has pre configured with root DNS server addresses.
Every single server can get to the root. So that only every DNS server on the Internet first contacts root DNS servers for name resolution.
Where can you find the address of root servers in the DNS server?
Open the DNS console è Right click on the domain name è drag down to properties è click on Root hints. Here you can find different root server addresses.
Note: When you install DNS service in a 2000 server operating system (still you have not configured anything on DNS server), then it starts its functionality as caching only DNS server.
What is caching only DNS server?
What is a forwarder?
(Open DNS console è Right click on Domain name è Click on forwarder tab)
A forwarder is server, which has more access than the present DNS server. May be our present DNS server is located in internal network and it cannot resolve the Internet names. May be it is behind a firewall or may it is using a proxy server or NAT server to get to the Internet. Then this server forwards the query to another DNS server that can resolve the Internet names.
Dynamic Host Configuration System (DHCP)
What is DHCP?
We can install DHCP by two ways
1)While installing Operating System
While installing Operating System, It asks at Network Settings whether u want Typical settings or Custom Settings
Select Custom SettingsèSelect Network Servicesèclick on DetailsèSelect DHCPèclick on OK
Programs èSettings èControl Panel èAdd/Remove Programs è Add/Remove Windows Components èSelect the Network ServicesèClick on properties èSelect DHCP èOK
(During the installation it asks for CD)
Programs èSettings èControl Panel èAdd/Remove Programs è Add/Remove Windows Components èSelect the Network ServicesèClick on properties èDeselect DHCP èOK
Open DHCP console by typing “dhcpmgmt.msc” at run prompt
Now you will find in DHCP console
Right Click on DHCP èClick on Add Server
Then you will get a window
Select the DHCP server
Now you will get
Servername.domain.com [IP address]
Note: Some time the window comes automatically with creating the “Add Server”. Such cases check the IP address whether it is correct or not. If it is wrong delete it and recreate it.
Now you have DHCP server.
Now you have to authorize the DHCP Server to provide IP addresses to the clients.
Who can authorize DHCP server in the entire domain?
An Enterprise administrator can only authorize DHCP server. No other person in the domain can authorize the DHCP server. Even if u r Administrator without enterprise administrator privileges you can’t authorize the DHCP server.
Note: If it is not authorized a red symbol (down red arrow) will appear, if u authorize it then a green up arrow will appear.
How to authorize the DHCP server?
Login with Enterprise administrator privileges.
Right Click on Servername.Domainname.com
Click on Authorize
Then it will be authorized (Indication is you will get green up arrow)
Now you have to create scope.
Note: A scope is range of IP addresses that you want to allocate to the clients.
How to create a scope?
Right click on servername.Domainname.com
Click on New Scope.
Click on Next.
Note: Generally we give the name as Network ID.
Click on Next.
Start IP address[______________________]
End IP address[______________________]
(Provide the starting IP address and End IP address)
Click on Next
Note: If you want to any exclusion you can do.
Starting IP address [______________]Ending IP address [__________]
What is the default lease duration, minimum lease duration and maximum lease duration?
By default any system will get 8 lease days to use IP address.
Note: You can increase or decrease the Lease duration, You have assign at least minimum duration of 1 second and you can assign Maximum duration of999 days 23 hours 59 minutes.
Note: If you haven’t log on for 50% of the duration continuously the IP address will be released.
Now you will get a Window asking whether you want to configure the options (DNS, WINS, and Router etc.)
You can configure the options now itself or you can authorize after completion of this.
Select any one then click Next.
Note: If u have selected “NO” in the above window you can configure above things anytime like below
Click on server optionèconfigure options è
Select the required ones
Enter server name, IP address
Now you have to activate the “Scope”
Right click on Scopeè Click on Activate
Note: You can reserve IP address for specific Clients. Or You can Exclude IP address (without allocation) for future purpose.
The above things all are in server.
Now you have to configure Client system.
Go to Client System
Right click on My Network Places èdrag down to properties è Right click on Local area connection èdrag down to properties è select TCP/IP è click on propertiesè
Now you will get one window containing TCP/IP properties
In that select “assign IP address automatically” and select “assign DNS address automatically”
Click on “More” delete the DNS suffix if anything is there.
Then the client takes IP address automatically from DHCP server.
The DHCP server also provides DNS, WINS, ROUTER addresses also.
Note: You must assign a static IP address for DHCP server.
(Generally in real time people will assign static IP address not only for DHCP server but also for all servers. Because if you assign automatic IP Address if DHCP is down then all servers will not function properly.)
Note: The DHCP server assigns IP address to the clients. But apart from that it also provides DNS address, default gateway, WINS address and so on, which are configured in DHCP server.
What is the protocol that is used for DHCP process?
To extend DHCP services beyond routers (IF “bootp” is not installed in router)
There are four stages in assigning IP address to a host by DHCP server.
When ever client has to obtain an IP address from a DHCP server it will broadcast a message called “DHCP discover” , which contains destination address 255.255.255.255 and source IP address as 0.0.0.0 and its MAC address.
The DHCP server on the network will respond to DHCP discover by sending a DHCP offer message to the client requesting an IP address.
The client after receiving offer message will send a “DHCP request” message asking the DHCP server to confirm the IP address it has offered to it through DHCP offer message.
DHCP server will respond to the “DHCP request” message by sending acknowledge message through which it confirms the IP address to other machine.
Note: You can also enable DHCP in work group for dynamic allocation of IP addresses.
Configure the server operating system in work group as a DHCP then go for client in TCP/IP properties select obtain IP address automatically. Then the client gets IP address from the DHCP server.
Note: You need not to configure DNS or anything.
On occasion, a network PC boots up and finds that the DHCP server is not available. When this happens, the PC continues to poll for a DHCP server using different wait periods.
The Automatic Private IP Addressing (APIPA) service allows the DHCP client to automatically configure itself until the DHCP server is available and the client can be configured to the network. APIPA allows the DHCP client to assign itself an IP address in the range of 169.254.0.1 to 169.254.254.254 and a Class B subnet mask of 255.255.0.0. The address range that is used by APIPA is a Class B address that Microsoft has set aside for this purpose.