Configuring Domain Name Files

Create or Modify the Resolver File

Create or Modify the Resolver File

The resolver file (RESLVCNF.NET.SYS) is an initialization file for the domain name resolver. It contains information needed by the network to determine how to resolve a domain name to an IP address. This file is read by the resolver routines the first time they are invoked by a process.

To create the resolver file, perform the following steps:

 

Step 1. Copy the sample file, RSLVSAMP.NET.SYS, to RESLVCNF.NET.SYS.

 

Step 2. Modify RESLVCNF.NET.SYS using any ASCII editor so that it contains

 

information about the name servers, domain, and search order for your

 

network. The keywords included in the file are described under “Fields.”

 

To modify an already existing RESLVCNF.NET.SYS file, simply use your

 

editor to update and save the existing file.

Fields

Each entry in the resolver file consists of a keyword followed by a value

 

separated by white space. The keyword and its associated value must

 

appear on a single line and the keyword must start the line. Figure 12-1

 

shows an example of a resolver file. Comment lines start with a pound

 

sign (#).

 

 

domain

Enter the local domain name. Most queries for names

 

 

within this domain can use short names relative to the

 

 

local domain name. If the host name does not contain a

 

 

domain part, the root domain is assumed. If more than

 

 

one instance of the domain keyword is present, the last

 

 

instance will override.

 

 

The domain name is composed of labels, with each label

 

 

separated by a period. Each label must start with a

 

 

letter or digit, and have as interior characters only

 

 

letters, digits, hyphens (-), or underbars (_). A domain

 

 

name may have any number of labels, but its total

 

 

length, including periods, is limited to 255 characters.

 

 

label[.label][...]

 

 

Domain names are not case sensitive.

 

search

The search entry is optional and indicates the order in

 

 

which domains should be searched for host name

 

 

lookup. You should add a search entry if users on this

system commonly try to connect to nodes in other domains. The search list is limited to six domains with a total of 256 characters. If more than one instance of the search keyword is present, the last instance will override.

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Chapter 12