Home > Articles > Operating Systems, Server > Microsoft Servers

The Domain Name System

  • Print
  • + Share This

Importing and Exporting BIND Databases

The data for standard primary zones are stored in database files that are compatible with BIND, making it convenient for you to move zones between BIND and Windows 2000 DNS servers. If you need to work with BIND, you will need to understand the formats of these files.

A BIND database file is required for each zone. The formats are different for forward and reverse lookup zones, so we'll need to consider them separately.

Additionally, BIND stores information about root name servers in a zone named CACHE. The format of the CACHE database file is similar to the format of a forward lookup database, but we will look at the CACHE file separately because of its particular significance.

Importing Data from BIND

If you have copies of the database files for BIND, it is easy to import the data into a zone that is hosted on a Windows 2000 DNS server. Refer back to the discussion about creating primary forward and reverse lookup zones and in particular to Figure 3.21.

In that dialog box, you have the option of supplying the name of a zone database file. Simply copy the BIND database files to the directory %systemroot%\system32\dns on the Windows 2000 Server and supply the name of the file when running the New Zone Wizard. When the zone is started, it will be initialized with data from the database file you supplied.

When importing the file, remember that BIND database files are created manually using a text editor. Administrators will have different styles for formatting these files, and you should review the files before attempting to import them to Windows 2000. However, the Windows DNS service should support all the features of BIND, and properly formatted resource records should import to Windows 2000 without problems.

To force an existing primary zone to import data from a text database file, do the following:

  1. Place the file in the directory %SystemRoot%\system32\dns.

  2. Open the properties for the zone and on the General properties tab, edit the Zone file name field so that it matches the name of the database file that is to be imported (refer to Figure 3.27).

  3. Open the properties pages for the server. On the Advanced tab, select From file in the field Load zone data on startup (refer to Figure 3.14).

  4. Restart the DNS service, or right-click the zone name in the object tree and select Reload from the context menu.

  5. Reset the value of the Load zone data on startup field if you want to store zone data in the Registry or in Active Directory.

The above procedure works only with primary zones. Secondary zones by definition obtain data from primary zones.

Exporting Data to BIND

As mentioned earlier, the data for standard primary and secondary zones are stored in BIND-compatible files. You will have to do more work when exporting to BIND than when importing to Windows 2000. Keep the following things in mind when exporting to BIND:

  • Remove any resource records from the database files that BIND does not understand. In particular, remove any WINS resource records.

  • Do not place copies of secondary zone database files on the DNS servers. Let BIND build its own database files by transferring the zone from a primary.

  • You will need to configure suitable boot configuration files for each server. Boot files are not created by Windows 2000 and are beyond the scope of this chapter.

  • Don't forget to set up the root CACHE database file.


Note

You can obtain an up-to-date copy of the root domain database file by using FTP to retrieve the file /domain/named.root from FTP.RS.INTERNIC.NET.


To force the Windows 2000 DNS service to update the text database files from its active database, do the following:

  1. Right-click a zone name in the DNS Management Console object tree.

  2. Select Update Server Data File from the context menu.

BIND Database File Formats

BIND database files are text files that are read when the name service is started. The name service on a BIND DNS server is called the Name Daemon. On UNIX systems, a daemon is a background process similar to a service on Windows 2000. The Name Daemon service is invoked using the command named.

The following sections review the formats of the database files for forward lookup, reverse lookup, and root cache zones.

Forward Lookup Database Files

The following listing is a simple database file for a forward lookup zone.

; Database file pseudo-corp.com.dns for pseudo-corp.com zone.
;   Zone version: 25
;
@            IN SOA dc1.pseudo-corp.com. administrator.pseudo-
corp.com. (
              25      ; serial number
              900     ; refresh
              600     ; retry
              86400    ; expire
              3600    ) ; minimum TTL
;
; Zone NS records
;
@            NS  dc1.pseudo-corp.com.
@            NS  dc2.pseudo-corp.com.
;
; Delegated sub-zone: paris.pseudo-corp.com.
;
paris          NS  dc2.pseudo-corp.com.
; End delegation
;
; Zone records
;
@            MX  10  mail1.pseudo-corp.com.
dc1           A  10.1.0.2
dc2           A  10.1.0.3
mail1          A  10.1.0.25
router         A  10.1.0.1
www           A  10.1.0.200
            A  10.1.0.201
            A  10.1.0.203
www1          A  10.1.0.200
www2          A  10.1.0.201
www3          A  10.1.0.203

If you understand two critical things about the database file, it is easier to relate the listing back to our work with the Windows 2000 DNS server:

  • Any text that follows a ; on a line is ignored. This convention enables administrators to format the file and insert comments.

  • The @ sign means "this zone," that is, the zone defined by this database file. It has the same meaning as the "(same as parent folder)" notation in resource records on the Windows 2000 DNS server.

Address resource records require little explanation. It is clear, for example, that

www           A  10.1.0.200

is a Host Address resource record that maps a hostname to an IP address. By convention, only the hostname is included in an address RR. The domain itself is implied. Fields in the database records are separated by whitespace (spaces or tabs). Typically, administrators supply enough spaces so that columns line up nicely.

To interpret resource records that contain an @ symbol, remember that @ means "this zone." For example,

@            MX  10  mail1.pseudo-corp.com.

means that mail1.pseudo-corp.com is a mail exchanger for pseudo-corp.com, because this zone database defines pseudo-corp.com.

The Start of Authority (SOA) RR makes use of both the conventions mentioned previously. First, because it begins with an @, the RR is known to apply to the zone that is associated with the current file.

Second, remember that all text between a ; character and the end of a line is ignored. In the SOA record, helpful comments were added to explain the purposes of the various parameters. Without the comments, the RR would look like this:

@            IN SOA dc1.pseudo-corp.com. administrator.pseudo-
corp.com. (25 900 600 86400 3600)

That isn't very clear unless you are experienced enough with BIND to remember the explanations of the settings.

Zone delegation requires at least two RRs: a Name Server (NS) and an Address (A) record. The following RRs are sufficient to delegate authority for paris.pseudo-corp.com:

paris          NS  dc2.pseudo-corp.com.

and

dc2           A  10.1.0.3

If the name server were not a host in the pseudo-corp.com zone, we would need to supply its FQDN with something like this:

name1.paris.pseudo-corp.com.   A  10.1.0.3

Note that this FQDN ends with a period to make it crystal clear that it ends with the root domain. Without the trailing period, it would be placed in the current domain, and the name would be interpreted as name1.paris.pseudo-corp.com.pseudo-corp.com. I warned you early in the chapter that there would be at least one instance where the root domain needs to be explicitly indicated with a trailing period, and this is it.

You shouldn't have much trouble relating the RRs in the text database file to the ones we have discussed. BIND database files aren't all that difficult to work with, when you know a few tricks.

Reverse Lookup Database Files

Here is an example of a BIND database file for a reverse lookup zone:

;
; Database file 1.10.in-addr.arpa.dns for 1.10.in-addr.arpa zone.
;   Zone version: 9
;

@            IN SOA dc1.pseudo-corp.com. administrator.pseudo-
corp.com. (
              9      ; serial number
              900     ; refresh
              600     ; retry
              86400    ; expire
              3600    ) ; minimum TTL

;
; Zone NS records
;

@            NS  dc1.pseudo-corp.com.
@            NS  dc2.pseudo-corp.com.
dc2.pseudo-corp.com.  A  10.1.0.3

;
; Zone records
;

1.0           PTR  router.pseudo-corp.com.
2.0           PTR  dc1.pseudo-corp.com.
25.0          PTR  mail1.pseudo-corp.com.
3.0           PTR  dc2.pseudo-corp.com.

The file isn't all that different from a forward looking database except that the bulk of the RRs are PTR records. To interpret the PTR records in the example, remember that the IP addresses for these hosts begin with 10.1. Therefore the RR

2.0           PTR  dc1.pseudo-corp.com.

is a pointer for host 10.1.0.2. (Remember that, for reverse lookup zones, the octets in the IP address appear in reverse order.)

There are a couple other things to note here. Notice that a hostname in a PTR RR is a FQDN with an explicit trailing period. Also notice that the database file includes a Host Address RR that enables the DNS server to locate host dc2, which is configured with a secondary copy of the zone.

The Cache Database File

The Cache zone was initially intended to designate frequently used RRs that should be loaded into the DNS server's cache when it was started. In time, however, the purpose of the Cache zone was limited to containing RRs pertaining to the root domain servers.

For the Internet root domain, the cache database contains entries like the following for each of the 13 root name servers:

; formerly NS.INTERNIC.NET
;
.            3600000 IN NS  A.ROOT-SERVERS.NET.
A.ROOT-SERVERS.NET.   3600000   A   198.41.0.4
  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020