By: James Beau Webb

Setting up DNS

I. What is DNS?

DNS is a service that you can have on your network. DNS stands for domain

name system or service, which basically takes a users request for a given

name of a device, and using the data that the server has for that device, it

maps the devices name to its ip address. Which is necessary because

networks don't run off of names, they use ip addresses. So the DNS allows

for devices to be located by name, so they can receive the data and packets

that are sent to them by their name. The most common example of this is with

the internet, everytime that a user puts in an internet address, for example

www.yahoo.com, the packet is sent to the DNS server, and the server maps

the domain name (yahoo.com) to its appropriate ip address, and then it

sends the user information to that address so the user can view the website.

DNS requires there be a DNS server, because the server is where all the

information is stored, and without it DNS would not be possible. You must

also have a list of all the DNS clients.The DNS server will not be able to

direct the data and information to the correct destination if it does not have

that device in its DNS database. So the DNS server needs a database that

consist of all the computers or devices on the network that are going to be

used in the DNS service.

The DNS database can be broken down into zones. A zone is when the

DNS server has a group of resource records that are related

because of the DNS domain name or because of the ip address.

There are two types of zones, a forward lookup zone and a reverse lookup

zone. The only difference in the two is that a forward lookup zone allows

names to be mapped to ip addresses, as to where the reverse lookup zone

maps ip addresses to their domain names. Also forward lookup zones

group information based on domain names, and these records are called

host records because they convert names to addresses. But reverse

lookup zones group their information by ip addresses, and these records

are called pointer records, and that's why they map ip addresses to

domain names. One other type of record the DNS database may contain

is an SRV record, which groups information based on DNS or network

services, so they resolve services to their names.

When you first create a forward or reverse lookup zone on a DNS server

you are creating the primary copy or the primary zone, and it can be read

or written to. The copies made of the the primary zone are called

secondary copies or zones, and they can only be read. It is strongly

recommended that you copy your zones to other DNS servers in case

something would happen to the server you are currently using.

II. How to install DNS on your network

First you must select a computer that you want to use as your DNS server.

Once you have that then you follow these steps to configure the DNS server

and service on the computer. This is for computers with Windows 2000:

1. Right click on My Computer on the desktop, once the menu appears

select Properties from it.

2. The System Properties box appears, then click on the Network

Identificaition tab. Which should look like this, with a different computer

name:

3. Then click the Properties button, and the Identification Changes window

should appear. Then press the More button and another window should

appear.

4. In the DNS Suffix and NetBIOS Computer Name window, you should

be able to set the the Primary DNS suffix for the computer to whatever

the DNS name for the network is or will be.

Notice: that the Primary DNS suffix is just ist.com , you should put

in your own domain name, but do NOT put in your computer name!

5. Once you have in the right domain name, press OK, and then press

OK again in the Identification Changes window. You should now be

back in the System Properties window, and the Full Computer Name

should now read: your computer name. your domain name

Like in the first picture, my Full Computer Name would be beau.ist.com

6. Now press OK in the System Properties window and restart the

computer to let the changes take effect.

7. Once the computer restarts, now go to START then to SETTINGS

and then to CONTROL PANEL, and select the "Add/Remove Programs"

applet.

8. Once the Add/Remove window appears, click on the "Add/Remove Windows

Components" option on the left hand side, and then Windows Component

Wizard should appear. Scroll down until you find the "Networking Services"

option. Once you find it just click on the "Networking Services" option one time

to highlight it, and then click the "Details" button. Then the Networking

Services window should appear.

9. Once the Networking Services window appears find the "Domain Name

System(DNS)" option and select it by clicking in the square box to the left

of it, and it should put a check mark in that box, and once the check mark

appears, then click OK. It should look like this:

Notice: you may have to insert the Windows 2000 CD to copy the files

and allow the installation to complete. Also you don't have to restart

after this if you don't want to, because the DNS will work without it.

To create a Primary Forward Lookup Zone:

Notice: make sure that you have done steps 1-6 completely before you

do the following, because you may experience problems with your

zones if you do the following before completely completing steps 1-6.

1. Go to START, then to PROGRAMS, then to ADMINISTRATIVE TOOLS,

and then to DNS, and click on DNS. The DNS window should appear.

Now on the left hand side of the screen, you should have a little icon for

a server, and the name of the server; double click on the server name.

2. Two folders should appear. Now right click on the words "Forward Lookup

Zones" and a menu should appear. On the menu select the "New Zone"

option and a New Zone Wizard should appear. Click "Next" to continue on.

3. Since you are setting up a Primary Forward Lookup Zone, the default setting

of "Standard primary" is what you want, so just click "Next" to continue.

4. Then the Zone Name window should appear, and here you just type in

the DNS domain name. DO NOT type in the host or computer name,

only the domain name. From the pictures above you have seen the

example of ist.com, so here is what it should look like with that as an

example (put your domain name in, not ist.com):

5. Then once you type in the domain name for the zone name, then just click

"Next" to continue on.

6. Now you should be at the Zone File window, and the wizard should already

have put your domain name that you just typed in for the file name, along with

the ".dns" extension at the end. So from my example it would be "ist.com.dns"

of course your's should have your domain name. Just go ahead and accept

this suggested file name, because it will be easy to remember, so just go

ahead and click "Next" to continue on.

7. Now you should see a Completion window which shows what you selected

or typed in to use for this forward lookup zone. It should look like this:

Except your's will of course have your domain name for the "Name" and

the "File name". Make sure to check all of the information in this

window to make sure everything has been properly selected and

typed in, especially the "Name" and make sure that you selected

the correct "Type" and "Lookup type" of zone that you wanted to

create, otherwise difficulties will occur.

8. Once you verified the information, go ahead and click "Finish" to complete

the setup and the wizard. Also, you should now see on the left hand side of

the DNS window a subfolder under the "Forward Lookup Zones" folder, and

that subfolder should be labeled with the domain name you specified for it,

for my example ist.com. On the right hand side on the DNS window you

should see a couple of default folders, and later as you add hosts to the

zone their will be records for each individual host added.

To create a Primary Reverse Lookup Zone:

1. Go to START, then to PROGRAMS, then to ADMINISTRATIVE TOOLS,

and then to DNS, and click on DNS. The DNS window should appear.

Now on the left hand side of the screen, you should have a little icon for

a server, and the name of the server; double click on the server name.

2. Two folders should appear. Now right click on the words "Reverse Lookup

Zones" and a menu should appear. On the menu select the "New Zone"

option and a New Zone Wizard should appear. Click "Next" to continue on.

3. Since you are setting up a Primary Reverse Lookup Zone, the default setting

of "Standard primary" is what you want, so just click "Next" to continue.

4. Now you should be at the Reverse Lookup Zone window were the

option of "Network ID" should be selected. That's what you want, so go

ahead and put in the network portion of your network ip address. This is

what it should look like, except with your network ip address:

Then click "Next" to continue on.

5. Now you should be at the Zone File window, and the top option to create

a the "Create a new file with this file name" option already selected, and that

is what you want, and it should have suggested a file name for you, which

should be the network ip address you just entered, but in reverse order, with

this following the reverse network portion of your network ip address,

"in-addr.arpa.dns". So the window should look like this, but with your network

portion of your network ip address:

6. Just go and accept the suggested name and click "Next" to continue on.

7. You should now be at the Completion window of the wizard. It looks like

the Completion window for the Forward Primary Lookup Zone, but with

different options of course because your making a Reverse Primary

Lookup Zone. Make sure to check all of the information in this

window to make sure everything has been properly selected and

typed in, especially the "Name" and make sure that you selected

the correct "Type" and "Lookup type" of zone that you wanted to

create, otherwise difficulties will occur.

8. Once you verified the information, go ahead and click "Finish" to complete

the setup and the wizard. Also, you should now see on the left hand side of

the DNS window a subfolder under the "Reverse Lookup Zones" folder, and

that subfolder should be labeled with the Network ID portion of your network

ip address that you specified for it. For my example its 10.0.0.x, which they

put the x in to fill in the host portion of the ip address. On the right hand side

on the DNS window you should see a couple of default folders, and

later as you add ip addresses for certain hosts, to the zone, their will be

a record for each individual ip address that you add into the zone. This is

what it should look like (and this example shows the 2 default records at

top of the right hand side, and beneath those 2 records are 3 records for

individual ip addresses added to the zone):

To create a Secondary Zone:

Before you try to create a secondary zone make sure that you know

the name of the zone and the ip address of the DNS server that

contains the primary zone.

1. Go to START, then to PROGRAMS, then to ADMINISTRATIVE TOOLS,

and then to DNS, and click on DNS. The DNS window should appear.

Now on the left hand side of the screen, you should have a little icon for

a server, and the name of the server; double click on the server name.

2. Two folders should appear. Now right click either on the words "Reverse

Lookup Zones" or "Forward Lookup Zone" depending on which one

you want or need to create and a menu should appear. On the menu select

the "New Zone" option and a New Zone Wizard should appear. Click

"Next" to continue on.

3. However, now we are creating a Secondary Zone, so this time select the

"Standard secondary" option on the Zone Type window, and then click

"Next" to continue on.

4. Now depending on which type of zone you are creating, will determine

what happens next. If you are creating a Forward Lookup Zone you will

be at the Zone Name window, where you have to enter the domain name

that you want to use for the new zone, the window should look like this:

Now if you are creating a Reverse Lookup Zone, then you will be at the

Reverse Lookup Zone window, where you have to enter the network

portion of your network ip address that you are creating this zone for.

This window should look like this:

Once you have put in the correct domain name for the zone name, or

you put in the correct network portion of the network ip address that

you want to use for this zone, then click "Next" to continue on.

5. Then you should be at the Master DNS Servers window, and both wizards

take you to this window, so it doesn't matter for this step which lookup type

you are creating. Here you need to enter the ip address of the master

DNS Server, which is the server that holds the primary zone. Once you

have entered the correct master DNS Server ip address then click "Add"

to add that ip address to the list that you want to copy the zone from.

So it should look like this once you have addedd the master DNS Server

address to the list, but the address should be for your master DNS

Server:

Once you have the master DNS server address in the bottom box, the

list box, then go ahead and click "Next" to continue on.

6. You should now be at the Completion window, which shows you what you

selected and entered to create this new zone. Make sure that the type

says "secondary". Make sure to check all

of the information in this window to make sure everything

has been properly selected and typed in, especially the "Name"

and make sure that you selected the correct "Type" and "Lookup

type" of zone that you wanted to create, otherwise difficulties will

occur.

7. Once you verified the information, go ahead and click "Finish" to complete

the setup and the wizard. Also, you should now see on the left hand side of

the DNS window a subfolder under the "Forward Lookup Zones" folder, or

under the "Reverse Lookup Zones" folder and that subfolder should be

labeled with the domain name you specified for it or the network ID of

the network ip address that you specified. On the right hand side on the

DNS window you should see a couple of default folders, and later

as you add hosts to the zone their will be records for each individual

host name or ip address that you add into the zone.

To add Records to your DNS Zone:

This is an important step, because if you don't have host records and PTR

records, then your DNS will not be able to map names to ip addresses, nor

will it be able to map ip addresses to their names. Now a host record is

stored in Forward Lookup zones and they store the devices name and its

ip address to allow the name to be mapped to its ip address.

But PTR records are stored in Reverse Lookup zones and they

store only the host portion of the ip address and the devices name so that

the ip address can be mapped to its name within that given network or

subnet. Notice that I said only the host portion of the ip address, because

the DNS service is setup only within that given network or subnet, therefore

the network portion of the address will always be the same, and that's why

only the host portion of the ip address is saved in the PTR record. You will

also have to add SRV records to the zones, which are service records

that need to be stored in the DNS database for use by the domain

controllers and the Active Directory services.

There are two ways that you can add these records, either manually or

dynamically. By doing this manually that means that you have to enter the

records yourself and as changes occur in the network, you must go back

and maintain the records to keep them correct and up-to-date. Or you

can go with the dynamic choice, which allows the DNS client or more likely

the DHCP server, which gives the client their ip address, to create the

records, and with this option when a change occurs the update is done by

the DNS server, DHCP server, or the client, and it is done automatically.

This means that little to no maintenance is required from you.

To manually add a Host Record:

1. Go to START, then to PROGRAMS, then to ADMINISTRATIVE TOOLS,

and then to DNS, and click on DNS. The DNS window should appear.

Now on the left hand side of the screen, you should have a little icon for

a server, and the name of the server; double click on the server name.

2. Now two folders should appear, one for Forward Lookup zones and one

for Reverse Lookup zones. Now right click on the subfolder that represents

your Forward Lookup Zone which you need to add a host record to. The

action menu should appear, and from it select the "New Host..." option

by clicking on it.

3. Now a New Host window should appear. Now in this window you need to

enter the host's name and their ip address information into the correct

boxes.

4. Once you have entered the host name and ip address, you the choice of

automatically creating the PTR record for this host for the Reverse Lookup

zone if that's what you want to do. To do this simply click in the check box

which is right below the ip address box and right next the words "Create

associated pointer (PTR) record".

Notice: In order to do the automatic PTR record, you must have

the Reverse Lookup Zone already created! Otherwise it will not

work.

This is what the New Host window should look like:

5. Once you have entered the host name and ip address, and either checked

or not checked the automatic PTR record option, then you can go ahead

and click the "Add Host" button to create the host record (and if you checked

the automatic PTR record it will also create the PTR record when you click

"Add Host"). You should now see on the right hand side of your DNS

window, this is once you have clicked on your Forward Lookup Zone

subfolder, you should see a record on the right hand side of the DNS

Window which has the host name that you entered and the type should

say "Host" and then you should see the ip address that you entered under

the data column.

If any of the information is wrong, simply right click on the host

record that is incorrect and select the "Properties" option from

the menu, and then you can change any incorrect information. Or

you can delete the old host record and just perform these steps

over again with the correct information.

To manually add a PTR record:

1. Go to START, then to PROGRAMS, then to ADMINISTRATIVE TOOLS,

and then to DNS, and click on DNS. The DNS window should appear.

Now on the left hand side of the screen, you should have a little icon for

a server, and the name of the server; double click on the server name.

2. Now two folders should appear, one for Forward Lookup zones and one

for Reverse Lookup zones. Now right click on the subfolder that represents

your Reverse Lookup Zone which you need to add a PTR record to. The

action menu should appear, and from it select the "New Pointer..." option

by clicking on it.

3. Now a New Resource Record window should appear. Now in this window you need to

enter the host's name and the domain name together, and their host portion

of their ip address into the correct boxes. It should look something like this:

4. Once you have entered the correct information into the correct boxes then

just go ahead and click the "OK" button to create the new PTR record

in your Reverse Lookup Zone. You should now see on the right hand

side of your DNS window, this is once you have clicked on your

Reverse Lookup Zone subfolder, you should see a record on the

right hand side of the DNS Window which has the correct ip address

for the client on your network, and the type should say "Pointer" and the

data should say the correct "host name.domain name" of the client.

To enable the other option, which is dynamic DNS:

In order for dynamic DNS to work you must do two things:

1. Configure the zone to accept dynamic updates

2. Configure the clients and/or DHCP to register ip addresses

with DNS.

To configure a zone for dynamic updates:

1. Go to START, then to PROGRAMS, then to ADMINISTRATIVE TOOLS,

and then to DNS, and click on DNS. The DNS window should appear.

Now on the left hand side of the screen, you should have a little icon for

a server, and the name of the server; double click on the server name.

2. Now two folders should appear, one for Forward Lookup zones and one

for Reverse Lookup zones. Now right click on the subfolder that represents

either your Forward Lookup Zone or your Reverse Lookup Zone, or which

ever zone of yours that you want to apply this to, and then click the

"Properties" option from the action menu. Now the Properties window

for that zone should appear.

3. The Properties window automatically comes up showing the General Tab,

now right above the "Aging" button is a drop down box with "No" showing

in it. To the left of this box you should see "Allow dynamic updates?". Now

what you need to do is just click on the down arrow at the end of that box,

and you should see the box expand to show "Yes" and "No". You need to

click on the "Yes" option. Now the box should say "Yes" instead of "No".

It should look like this:

Once you have "Yes" showing in that box then click the "OK" button.

Now to configure the client's DNS update configuration:

1. Go to the client's machine or have the client to do so, and go to the Start

menu, then go to Settings, then go to Network and Dial-up Connections and

click on it. Then the Network and Dial-up Connections window should appear.

2. Now double click on the Local Area Connection icon.

Then the Local Area Connection Status window should appear, and there

should be a "Properties" button, click it. Then the Local Area Connection

Properties window should appear.

3. The Local Area Connection Properties window will automatically show the

General Tab, and on that tab you should see a box in the middle, which has

"Internet Protocol (TCP/IP)" as the bottom option. Click on that option one

time just to highlight it, then go and click the "Properties" button. Now the

Internet Protocol (TCP/IP) Properties window should appear, and on the

General Tab you should see close to the bottom an "Advanced" button,

click it. Now the Advanced TCP/IP Settings window should appear.

4. In the Advanced TCP/IP Settings window select the DNS Tab, and the DNS

information is displayed. Now close to the bottom, just above the "OK" and

"Cancel" buttons are two check boxes. The top check box says "Register

this connection's addresses in DNS", you need to check that check box

for that option if it is not already checked. It should look like this:

5. Once you know that this option has a check in it's box to enable it,

then go ahead and click "OK".

That is all you have to do to enable dynamic DNS!

Now if you prefer, you can have the DHCP server to register the ip

addresses it gives out to it's clients to the DNS server, which would

eliminate the user having to check to make sure that their machine

allows the "Register this connection's addresses in DNS" option, but

you have to configure the DHCP server to do this. If you want to do this

see Windows 2000 Help, or look at the DHCP manual.