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This section of the Configuring and Managing MPE/iX Internet Services
manual assumes that the reader has prior experience with DNS BIND
as implemented on other operating systems, or has familiarity with
the concepts involved. There are a number of good textbooks available
on this subject to which the reader is recommended — the
following is a brief overview of a sophisticated system.
The Domain Name System is a distributed and structured directory
of information. One of its more frequent uses is the naming of host machines.
A DNS host name will consist of several fields separated by dots,
for example:
quasar.india.hp.com.
The host quasar exists in the domain india, which itself is a
subdomain of hp, which is a subdomain of com, which is a
subdomain of the root domain (identified as ".").
With this structured naming convention, the responsibility for maintaining
accurate database information for a name domain can be delegated to a server
which is managed by the organization who owns that domain. for example, DNS
server hosts within HP maintain information about hp.com. Queries for
names inside the domain hp.com will be referred to that server by
servers in other domains. Within HP, the responsibility for
india.hp.com can also be delegated to another local DNS server.
Before MPE/iX 6.0, hosts running MPE/iX were able to make
DNS queries of servers running on other machines and operating systems. Now
a full implementation of the server code has been introduced. DNS BIND/iX
will enable your MPE/iX host to act as a DNS server, both responding
to queries (from clients and other servers) as well as communicating
with other DNS servers on the local network and the Internet.
The way this information is accessed is through client programs
or code routines called "resolvers". When a program
on a client host needs to obtain information about a domain, it
will send a message to the local DNS server host. If the local server
has this information, it will send back a reply immediately. If
the local server does not have this information, it will research
by sending queries to other servers, following the Domain Name System
structure. Once the local server has found an answer for the client,
it will then reply, but will also cache what it has learned in order
to respond more speedily to subsequent queries.
DNS BIND/iX on MPE/iX 6.0 is an implementation of BIND version 8.1.1,
which has introduced many new features since the more commonly used
version 4.9.4, (with which the majority of experienced DNS users
will be familiar).
This is the latest version of BIND, 8.1.1. with features like:
DNS Dynamic updates
DNS change notification
completely new configuration syntax
flexible and categorized logging system
more efficient zone transfers
The package contains a host of utilities and administration tools:
nslookup — query Internet name servers interactively
dig — Domain Information Groper
host — look up host names using domain server
addr — get address of host
dnsquery — give all the DNS details and Mail exchange
records
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