Tjenester

dnsmasq - DNS og DHCP

Her laver vi en opsætning med dnsmasq

Klargøring af server

Først skal vi have fjernet standardsystemet.

systemctl disable --now systemd-resolved
sudo systemctl stop systemd-resolved
sudo rm -rf /etc/resolv.conf

Indsæt Google's DNS så vi kan installere dnsmasq senere.

echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf

Åbn firewall'en

Serveren skal have åbnet port 53 i firewall'en, så andre computere kan komme til DNS'en

sudo ufw allow 53

Vil du tjekke firewall'ens status kører du kommandoen:

sudo ufw status
Status: active To Action From -- ------ ---- OpenSSH ALLOW Anywhere 53 ALLOW Anywhere OpenSSH (v6) ALLOW Anywhere (v6) 53 (v6) ALLOW Anywhere (v6)

Installer dnsmasq

sudo apt install dnsmasq dnsutils ldnsutils -y

Rediger filen /etc/dnsmasq.conf

sudo nano /etc/dnsmasq.conf

Indsæt følgende øverst i filen, for at

port=53 domain-needed bogus-priv no-resolv cache-size=250 server=8.8.8.8 server=8.8.4.4 #use two lines below to resolve local domains (eg .home) local=/home/ domain=home

Tjek at dnsmasq er sat korrekt op og genstart dnsmasq med den nye konfiguration

dnsmasq --test

Sæt navneserveren til den lokale computer:

echo "nameserver 127.0.0.1" | sudo tee /etc/resolv.conf

Ret filen /etc/hosts, så serveren får adressen server.home.

sudo nano /etc/hosts
127.0.0.1 localhost 127.0.1.1 server1 192.168.87.11 server.home # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters

Genstart dnsmasq

systemctl restart dnsmasq

Tjek at DNS'en virker

dig server.home +short
tj@server1:~$ dig server.home +short 192.168.87.11

Hvis du vil ændre din computers navn (fra server1 til f.eks. server.home), så skal du bruge guiden her: Ændring af hostename

Done!

Indhold af filer

/etc/hosts

127.0.0.1 localhost 127.0.1.1 server1 192.168.87.10 server.home # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters

/etc/hostname

server1

/etc/resolv.conf

nameserver 127.0.0.1

https://www.howtoforge.com/how-to-setup-local-dns-server-using-dnsmasq-on-ubuntu-20-04/

https://computingforgeeks.com/install-and-configure-dnsmasq-on-ubuntu-18-04-lts/

https://askubuntu.com/questions/1092727/how-can-i-create-a-local-dns-that-is-seen-from-other-computers-on-my-local-netwo