DNS is short for Domain Name System, which consists of resolvers and domain name servers.
A domain name server refers to a server that stores the domain names and corresponding IP addresses of all hosts in the network and has the function of converting domain names to IP addresses.
The domain name must correspond to an IP address, and the IP address does not necessarily have a domain name
DNS is a server for domain name resolution
yum install bind* -y
Server configuration file path /var/named/redhat.com.zone
Client configuration file path /etc/resolv.conf
Need to use named.service
Forward DNS configuration
vim /etc/named.conf
options {
listen-on port 53 { 10.100.52.169; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { any; };
allow-query-cache { any; };
recursion yes;
forwarders {114.114.114.114;};
};
logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
zone "." IN {
type hint;
file "named.ca";
};
zone "example.com" {
type master;
file "example.com.zone";
};
/var/named/redhat.com.zone
Regional configuration
/var/named
$TTL 1D
@ IN SOA redhat1.example.com. [email protected]. †
201206 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
@ IN NS redhat1.example.com.
redhat1 IN A 10.100.52.169
redhat2 IN A 10.100.52.169
~
bbs IN A www CNAME
Add CNAME to visit bbs.redhat.com
windows test DNS
First modify the local DNS
Enter the IP address of the server in the preferred DNS server in the IPV4 properties of the network connection
Install httpd server
Write the content in /var/www/html/index.html of the server and client respectively
Restart the server and client services separately
Log in to the website built by yourself through the browser
linux command line test
vim /etc/resolv.conf Modify DNS
nameserver 172.16.40.127
command line input
you www.redhat.com
Can see DNS IP
Forward batch parsing
Add function to configuration file
$GENERATE 1-200 station$ IN A 172.16.40.$
The host name can be resolved by adding a number from 1 to 200
Test First change the hostname
you station50.redhat.com
Change the hostname to station100.redhat.com
Entering station100.redhat.com in the browser can also resolve to
reverse parsing
/etc/named.conf (see if it is added)
options {
listen-on port 53 { 172.16.40.2; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { any; };
allow-query-cache { any; };
recursion yes;
};
zone "." {
type hint;
file "named.ca";
};
zone "example.com" {
type master;
file "example.com.zone";
};
zone "40.16.172.in-addr.arpa"{
type master;
file "40.16.172.in-addr.arpa.zone";
file "172.16.40.arpa"; (test whether to add)
};
vim /var/named/40.16.172.in-addr.arpa.zone
Add to
$TTL 1D
@ IN SOA dns.redhat.com. [email protected]. †
201206 ;
5m ;
15m ;
1W ;
3h );
@ IN NS dns.redhat.com.
127 IN PTR www.redhat.com.
127 IN PTR www.redhat.com.
128 IN PTR server.example.com.
Reverse parsing can only be tested with the command line
Add nameserver server IP in client /etc/resolv.conf
Forward nslookup www.redhat.com
reverse dig -x IP
dig is forward parsing
Reverse batch parsing adds $GENERATE $1-200 IN PTR station$.redhat.com.
reverse batch parsing dig -x 172.16.40.200
Secondary DNS mentions fault tolerance to speed up queries
Need to open another virtual machine to assist
yum install bind
vim /etc/named.conf
options {
listen-on port 53 { 172.16.40.129; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { any; };
allow-query-cache { any; };
recursion yes;
};
zone "." {
type hint;
file "named.ca";
};
zone "redhat.com" {
type slave;
file "slaves/redhat.com.zone"；
masters{172.16.40.127;};
};
zone "40.16.172.in-addr.arpa"{
type slave;
file "slaves/40.16.172.in-addr.arpa.zone";
masters {172.16.40.127;};
};
vim /var/named/slaves/redhat.com.zone
save and exit
vim /var/named/slaves/40.16.172.in-addr.arpa.zone
save and exit
cd / var / named
Modify slaves permissions 766 to use recursion
cd / var / named / slaver
Check if there are new files in this directory