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DNS• DNS - Domain naming system.
• DNS service locates and translatesdomain names into correspondingassociated IP addresses.
• DNS configuration.
• It requires the following softwarepackages to be installed.• bind• Caching-name server• bind-utils
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Thus the DNS makes it possible to ping anhost by its domain name by resolving the
domain name into IP address.
DNS Configuration
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Forward zone lists the name
servers outside the network that
should be searched when the
networks name server fails.
DNS Configuration
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Service profile
• Packages - bind, bind-utils,
• caching-nameserver
• Configuration files - /etc/named/named.conf
• /var/named/named.local
• Daemons - named
• Port number - 53
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Install bind, this package
includes web page
manuals anddocumentation
Install bind-utils which
provides many utilities
like host, dig and nslookup
Install caching-name
server which provides a
working named.conf configuration file
DNS Configuration
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Open this file for mentioning
the home directory for DNS.
DNS Configuration
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Here DNS home directory
is /var/named/chroot.
DNS Configuration
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View the home
directory files.
DNS Configuration
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Open the configuration
file named.conf.
DNS Configuration
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Now you are seeing
the contents of
named.conf file.
DNS Configuration
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Forward zone mapping
between fully qualified
domain to particular ip
address.
This file contains
the ip address andthe locations of all
the dot servers.
DNS Configuration
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DNS Configuration
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Enter theforward file
name.
Copy and paste the forward
and reverse zones and edit
them as follows.Enter the
domain name
here.
Enter the IP
address in
reverse order.
Enter the
reverse file
name.
DNS Configuration
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Save and exit the
file
DNS Configuration
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Copying the syntax file
named.local to example.for
and example.rev.
DNS Configuration
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Open the forward
file.
DNS Configuration
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Enter the fully qualified
name of the name
server.It is interpreted as the
name of the originating
domain.
Enter the authorised name
server for this zone.
Enter the fully qualified
name of host.
Enter the last number segment
of the host address in thereverse zone file.
DNS Configuration
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Replace local host to fully
qualified name using asgiven below.
DNS Configuration
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Now the localhost is replaced as
server1.example.com.
DNS Configuration
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Enter the ip address for
specified domain name.
Canonical name, is used to
define an alias for a hostname.
Set www as the cname for
server1.example.com.
DNS Configuration
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Open the
example.rev file.
DNS Configuration
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DNS Configuration
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Replace localhost to
server1.example.com using as below.
DNS Configuration
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Now the localhost is replaced
by server1.example.com.
DNS Configuration
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In a PTR record, you can specify
just that last number segment of
the address.
DNS Configuration
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Open the
resolve.conf file.
DNS Configuration
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Mention the nameserver
ipaddress and domain name here.
DNS Configuration
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Now named service
is restarted.
DNS Configuration
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Thus the DNS makes it possible to ping an
host by its domain name by resolving the
domain name into IP address.
DNS Configuration
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Thus the DNS makes it possible to ping an
host by its domain name by resolving the
domain name into IP address.
DNS Configuration
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dig command shows ip addressof the specified fully-qualified
domain name .
DNS Configuration
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Nslookup is a dns diagnostic tool
used to query a dns server.
Using nslookup you can identifies
nameserver for particular doamin.Using nslookup you can identifies
address for particular FQDN.
Using nslookup you can identifies
FQDN for particular IP address.
DNS Configuration
fi i
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Thus the DNS makes it possible to ping anhost by its domain name by resolving the
domain name into IP address.
DNS Configuration
S C fi i
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In client side open the
/etc/resolv.conf file.
DNS Configuration
DNS C fi i
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Mention the nameserver
ipaddress and domain name
here.
DNS Configuration
DNS C fi i
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Thus the DNS makes it possible to ping an
host by its domain name by resolving the
domain name into IP address.
DNS Configuration
DNS C fi i
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It shows the simple lookup of
host,thus its show the
corresponding ip address to thespecified fully quailed domain
name.
Using nslookup you can identifies
MX record for particular domain.
Using nslookup you can identifiesnameserver for particular domain.
DNS Configuration
DNS C fi i
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Open the forward
file.
DNS Configuration
DNS C fi ti
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In this file we can add additional
entry MX(mail exchange record )
and its corresponding ip address
192.168.0.100.In this file we can add additional
entry station105 machine and its
corresponding ip address
192.168.0.100
DNS Configuration
DNS C fi ti
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Open the reverse
file.
DNS Configuration
DNS C fi ti
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Similarly we can add another
pointer record 105 for
station105.example.com.
DNS Configuration
DNS C fi ti
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Now named service
is restarted.
DNS Configuration
DNS C fi ti
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Using nslookup you can identifies
MX record for particular domain.Using nslookup you can identifies
address for particular FQDN.
Using nslookup you can identifies
PTR record for particular FQDN.
DNS Configuration
DNS C fi ti
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Open the configuration
file named.conf.
DNS Configuration