= DNS on BSD =

'''Domain Name Resolution''' ('''DNS''') was [[Bind|invented for BSD]], so in many ways ''DNS for BSD'' is just textbook DNS.

<<TableOfContents>>

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== Name resolution ==



=== Name Service Switch ===

The [[BSD/NsSwitchConf|Name Service Switch (NSS) configuration file]] (`/etc/nsswitch.conf`) defines the order of operations for various services, among them being name resolution.

{{{
hosts: files dns
}}}



=== Hosts ===

The [[Linux/Hosts|hosts file]] (`/etc/hosts`) is a list of addresses and names, especially for local hosts and machines.

{{{
127.0.0.1 localhost
}}}



=== Resolver ===

The [[Linux/ResolvConf|resolver configuration file]] (`/etc/resolv.conf`) is a list of nameservers to query for name resolution. Changes are immediately effective.

It isn't recommended to manage this file directly. Instead, allow [[Dhclient|dhclient(8)]] and [[OpenResolv|resolvconf(8)]] to overwrite the file and configure the behavior of those programs.

At any time, the resolver file can be re-generated by running `resolvconf -u`.



=== Utilities ===

 * `drill(1)`, used as `drill NAME @SERVER TYPE`
 * [[Bind/Dig|dig(1)]]

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== Multicast name resolution ==

'''Multicast domain name resolution''' ('''mDNS''') is an expansion of the DNS protocol. An mDNS broadcaster makes use of port 5353 and resolves names in the `.local` domain.

There is no mature implementation of mDNS for the BSDs. [[Avahi]] ''may'' work; [[OpenMDNS]] was designed for use in [[BSD/OpenBSD|OpenBSD]] and may be more compatible.



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