test

Netra j 2.0 Administrator's Guide

Configuring the DNS Server

Configuring the DNS server is a two-step process:

  1. Start a name server. Unless you are running a root name server, you must specify a list of other name servers that will be queried when the local DNS server cannot resolve a query. The default list of name servers should be sufficient for all sites connected directly to the Internet. For sites that do not have direct access (for example, because they are behind a firewall), list other DNS servers that can be contacted.

  2. Once the DNS server is running, add primary and secondary domains as needed.

When a primary domain is added, enter the name of the domain and host name/host address pairs for the machines on the domain. In addition, host aliases (CNAME records), information about mail servers (MX records), and/or other name servers may be entered. To configure the Netra server as a root server, enter the domain name root and add the names of the DNS primary domain servers in the name servers field.

When adding a secondary domain, specify the name of a domain and the IP address of a DNS server for that domain. The Netra server copies and cache all the information about this domain in anticipation to queries.

To Configure the Netra Server as a DNS Server

If you configure the Netra server as a DNS server, it is usually best to also configure the Netra server to be a client of this DNS server. You must configure the DNS server first and then configure it as a client.

  1. From the Main Administration page, under "Network Services Administration," click Name Service, then click DNS (Domain Name Service).

  2. Under "DNS Administration," click Configure DNS Server.

    The DNS Server Administration page is displayed.

  3. Complete the form using the information in Table 3-6.

    Table 3-6 DNS Server Administration

    DNS Server Information 

    Description 

    DNS Domain Name 

    The DNS domain in which the Netra server resides. The domain name is assumed to be fully-qualified (do not use a trailing period). Example: comedy.tv.net

    Root Name Servers/ Host Addresses 

    The fully qualified host names and host addresses of DNS name servers to contact to resolve name service queries. If the Netra server is behind a firewall, use the names and addresses of name servers on the firewall. If the Netra server is a root name server, this field can remain empty. Example: access.isp.net 129.144.102.6

    Generate Reverse Maps 

    When this box is checked, Netra automatically generates the reverse maps (address to name records) for every host address/host name pair entered when configuring a primary domain. This assumes that the IN-ADDR.ARPA authority has been delegated to your site. Consult with your Internet Service Provider before changing the default checked state.  

To Modify or Delete a DNS Server

  1. From the Main Administration page, under "Network Services Administration," click Name Service, then click DNS (Domain Name Service).

    The DNS Administration page is displayed.

  2. Choose one of the following:

    • To modify a DNS server, click Modify, and make the changes in the form using Table 3-6 as a reference.

    • To delete a DNS server, click Delete; then confirm the operation.

To Configure the Netra Server as a DNS Primary Server

  1. From the Main Administration page, under "Network Services Administration," click Name Service, then click DNS (Domain Name Service).

  2. Under "DNS Administation," click Add a primary domain.

    The Add DNS Primary Domain page is displayed.

  3. Complete the form using information in Table 3-7.

    Table 3-7 DNS Primary Server Administration

    DNS Primary Server Information 

    Description 

    Primary Domain Name 

    The name of the primary domain. If the Netra server is a root name server, use the domain name root. The domain name is assumed to be fully qualified (do not use a trailing period). Example: elmo 129.144.79.1

    Host Names/Host Addresses 

    The host names and corresponding host addresses of the hosts within the specified domain. 

    Host Aliases/Host Names 

    The host aliases within this domain and their corresponding host names. A host name must be within the domain, unless it is a fully qualified host name. 

    Mail Addresses/ Mail Server/ Preferences 

    The mail address, the corresponding mail server, and its preference value.  

    o The mail address is a host name or an alias and must be within the domain. 

    o The mail server is the machine that will accept mail for this address. If there is more than one mail server, the preference value determines which mail server is used.  

    o The preference value is an integer: the lower the value, the higher the priority of that mail server. 

    Domains/ DNS Servers 

    The domains served by the corresponding DNS name servers. The domain must be a subdomain of the primary domain, unless it is a fully qualified domain name. The host name of the name server must be within this domain, unless it is a fully qualified host name. All DNS servers will be treated as authoritative for the listed domain. If a subdomain is entered, authority for that domain is delegated to the listed server. Do not enter the Netra server or primary domain. 

For example, assume that a master database for the domain comedy.tv.net is to be set up. In the Primary Domain Name field, specify: 

comedy.tv.net

In the Host Names/Host Addresses field, type a list of those hosts whose presence are to be broadcast to any machine which can connect to this DNS server. For this example, type ren, stimpy, and homer, a host that resides on the subnet black.comedy.tv.net. 

ren							129.1.1.2
stimpy							129.1.1.3
homer.black							129.2.1.2

The Internet community uses conventional names for hosts that provide certain types of services, in order to make them easy to locate. For instance, the WWW server for a domain is usually known as www.domain and an anonymous FTP server is typically called ftp.domain. On comedy.tv.net, ren is an FTP and WWW server, while stimpy is a name server. Standard aliases for these machines are added into the Host Aliases/Host Names field 

www							ren
ftp							ren
ns							stimpy
:

stimpy is going to handle mail sent to comedy.tv.net so an MX record needs to be created: 

comedy.tv.net						5 		stimpy

If a domain contains subdomains, the DNS primary domain server for the domain must know a DNS server for the subdomain. comedy.tv.net has a subdomain called black, whose DNS primary domain server is called homer. homer resides on that domain, so in order for the Netra DNS server to reach homer when it needs to request name services for that domain, it has to know homer's IP address. That is why homer.black was added to the list of known hosts.

To Modify or Delete a DNS Primary Domain

  1. From the Main Administration page, under "Network Services Administration," click Name Service, then click DNS (Domain Name Service).

    The DNS Primary Domain page is displayed.

  2. Choose one of the following:

    • To modify a DNS primary domain, click Modify, and make the changes in the form using Table 3-7 as a reference.

    • To delete a DNS primary domain, click Delete; then confirm the operation.

To Configure the Netra Server as a DNS Secondary Server

  1. From the Main Administration page, under "Network Services Administration," click Name Service, then click DNS (Domain Name Service).

  2. Under "DNS Administration," click Add a secondary domain.

    The Add DNS Secondary Domain page is displayed.

  3. Complete the form using the information in Table 3-8.

    Table 3-8 DNS Secondary Server Administration

    DNS Secondary Server Information 

    Description 

    Secondary Domain Name 

    The name of the secondary domain. Use the domain name root if the Netra system is a secondary server for the root domain. The domain name is assumed to be fully qualified (do not use a trailing period). Example: tv.net

    Master DNS Servers' Host Addresses 

    The host addresses of the master DNS name servers in the order in which they should be queried. A master DNS server can be either an existing primary or secondary DNS server. Example: 129.144.102.6

To Modify or Delete a DNS Secondary Domain

  1. From the Main Administration page, under "Network Services Administration," click Name Service, then click DNS (Domain Name Service).

    The DNS Secondary Domain page is displayed.

  2. Choose one of the following:

    • To modify a DNS secondary domain, click Modify, and make the changes in the form using the information in Table 3-8.

    • To delete a DNS secondary domain, click Delete then confirm the operation.

    Note -

    If a Netra server configured as a DNS server is installed on top of an operational system that is configured as a NIS server, the NIS server prevents the DNS server from running correctly unless it is configured to co-exist with DNS. To ensure that it is, edit the /var/yp/Makefile file (which makes the NIS server), replacing the line B= with B=-b and then run make.