Dnsmasq : Install and Configure2021/07/23

	Install Dnsmasq that is the lightweight DNS forwarder and DHCP Server Software.
[1]	Install Dnsmasq.

[root@dlp ~]#

dnf -y install dnsmasq

[2]	Configure Dnsmasq.

[root@dlp ~]#

vi /etc/dnsmasq.conf

# line 19 : uncomment

# never forward addresses in the non-routed address spaces

domain-needed

# line 21 : uncomment

# query with each server strictly in the order in resolv.conf

bogus-priv

# line 53 : uncomment

# query with each server strictly in the order in [resolv.conf]

strict-order

# line 67 : add if you need

# query the specific domain name to the specific DNS server

# example below means query [server.education] domain to [10.0.0.10] server

server=/server.education/10.0.0.10

# line 135 : uncomment

# add domain name automatically to hostnames

expand-hosts

# line 145 : add your own domain name

domain=srv.world

[root@dlp ~]#

systemctl enable --now dnsmasq

[3]	For DNS records, add them in [/etc/hosts]. Then, Dnsmasq will answer to queries from client hosts.

[root@dlp ~]#

vi /etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
# add records
10.0.0.30   dlp.srv.world dlp

[root@dlp ~]#

systemctl restart dnsmasq

[4]	If Firewalld is running, allow DNS service. DNS uses [53/TCP,UDP].

[root@dlp ~]#

firewall-cmd --add-service=dns

success
[root@dlp ~]#

firewall-cmd --runtime-to-permanent

success

[5]	Verify Name or Address Resolution from a client host in your network.

[root@node01 ~]#

dnf -y install bind-utils

# change DNS to Dnsmasq Server (replace [enp1s0] to your own environment)

[root@node01 ~]#

nmcli connection modify enp1s0 ipv4.dns 10.0.0.30

[root@node01 ~]#

nmcli connection down enp1s0; nmcli connection up enp1s0

[root@node01 ~]#

dig dlp.srv.world.


; <<>> DiG 9.11.26-RedHat-9.11.26-4.el8_4 <<>> dlp.srv.world.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50154
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;dlp.srv.world.                 IN      A

;; ANSWER SECTION:
dlp.srv.world.          0       IN      A       10.0.0.30

;; Query time: 2 msec
;; SERVER: 10.0.0.30#53(10.0.0.30)
;; WHEN: Fri Jul 23 11:41:18 JST 2021
;; MSG SIZE  rcvd: 58

[root@node01 ~]#

dig -x 10.0.0.30


; <<>> DiG 9.11.26-RedHat-9.11.26-4.el8_4 <<>> -x 10.0.0.30
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<-v opcode: QUERY, status: NOERROR, id: 2360
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;30.0.0.10.in-addr.arpa.                IN      PTR

;; ANSWER SECTION:
30.0.0.10.in-addr.arpa. 0       IN      PTR     dlp.srv.world.

;; Query time: 0 msec
;; SERVER: 10.0.0.30#53(10.0.0.30)
;; WHEN: Fri Jul 23 11:41:53 JST 2021
;; MSG SIZE  rcvd: 78

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