5 linux managing dns servers lpic 2 m5 slides kho tài liệu training

•
•
•
•





$ nslookup -querytype=mx pluralsight.com
$ nslookup


server 127.0.0.1



set type=mx



pluralsight.com



………..



set debug



web.theurbanpenguin.com


$ dig pluralsight.com -t mx
$ dig pluralsight.com +short -t mx


$ host www.pluralsight.com

# Returns A Record

$ host 8.8.8.8

# Returns PTR Record



#!/usr/bin/perl
use strict;
use warnings;
use Net::DNS::Resolver;
my $hostname;
print(“Enter a hostname: “);
chomp($hostname = <STDIN>);


my $resolver = Net::DNS::Resolver->new(

nameservers => [qw(8.8.8.8)],
);
my $query = $resolver->search($hostname);


if ($query) {
foreach my $record ($query->answer) {
next unless $record->type eq "A";
print(“Answer: " . $record->address . "\n");

}
}



$ sudo apt-get install -y python3-dnspython


#!/usr/bin/python3
import dns.resolver
resolver = dns.resolver.Resolver()

answers = resolver.query("docker.theurbanpenguin.com","A")
for answer in answers:
print(answer)



•

•
•
•
•
•