Domain Name System (DNS)
DNS🔗
Domain Name System (DNS) #tech/networking/DNS
DNS: hierarchical and distributed naming system
mDNS: multicast DNS for local networks
Machines have an A record to be identified. It maps a domain name to the IP (4/6) address of the computer hosting the domain. Usually is the same as the hostname for convenience and to avoid confusion. In addition there can be an arbitrary number of CNAME. Also see FQDN (full qualifies domain name).
To reduce the amount of requests/traffic, usually a (local) cache is used.
- basic DNS resolution config in
/etc/resolv.conf
DNS lookup
1 2 3 4 | |
DNSSEC (DNS Security Extensions)
| IP address | Provider | Description |
|---|---|---|
| 1.1.1.1 | Cloudflare | |
| 1.1.1.2 | Cloudflare | location based filtering providing some security |
| 1.1.1.3 | Cloudflare | additional adult content filtering |
| 8.8.8.8 | ||
| : Public DNS servers |
Tools🔗
- Dnsmasq: “Dnsmasq provides network infrastructure for small networks: DNS, DHCP, router advertisement and network boot.”