Difference between revisions of "Resolv.conf"
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:''"On a normally configured system this file should not be necessary. The only name server to be queried will be on the local machine; the domain name is determined from the host name and the domain search path is constructed from the domain name."'' | :''"On a normally configured system this file should not be necessary. The only name server to be queried will be on the local machine; the domain name is determined from the host name and the domain search path is constructed from the domain name."'' | ||
| − | ==Preserve DNS settings== | + | == Preserve DNS settings == |
| + | |||
{{Pkg|dhcpcd}}, [[NetworkManager]], and various other processes can overwrite {{ic|/etc/resolv.conf}}. This is usually desirable behavior, but sometimes DNS settings need to be set manually (e.g. when using a static IP address). There are several ways to accomplish this. If you are using NetworkManager, see [https://bbs.archlinux.org/viewtopic.php?id=45394 this thread] on how to prevent it from overriding your {{ic|/etc/resolv.conf}}. | {{Pkg|dhcpcd}}, [[NetworkManager]], and various other processes can overwrite {{ic|/etc/resolv.conf}}. This is usually desirable behavior, but sometimes DNS settings need to be set manually (e.g. when using a static IP address). There are several ways to accomplish this. If you are using NetworkManager, see [https://bbs.archlinux.org/viewtopic.php?id=45394 this thread] on how to prevent it from overriding your {{ic|/etc/resolv.conf}}. | ||
| − | ===Modify the dhcpcd Config=== | + | === Modify the dhcpcd Config === |
| + | |||
dhcpcd's configuration file may be edited to prevent the dhcpcd daemon from overwriting {{ic|/etc/resolv.conf}}. To do this, add the following to the last section of {{ic|/etc/dhcpcd.conf}}: | dhcpcd's configuration file may be edited to prevent the dhcpcd daemon from overwriting {{ic|/etc/resolv.conf}}. To do this, add the following to the last section of {{ic|/etc/dhcpcd.conf}}: | ||
nohook resolv.conf | nohook resolv.conf | ||
| − | ===Use resolv.conf.head=== | + | {{Note|If you use [[netctl]] and static IP address assignment, do not use the {{ic|DNS*}} options in your profile, otherwise ''resolvconf'' is called and {{ic|/etc/resolv.conf}} overwritten.}} |
| + | |||
| + | === Use resolv.conf.head === | ||
| + | |||
| + | {{Expansion|When using {{Pkg|openresolv}}, this can be done also in {{ic|/etc/resolvconf.conf}} using the {{ic|name_servers}} and {{ic|name_servers_append}} options.}} | ||
| + | |||
Alternatively, you can create a file called {{ic|/etc/resolv.conf.head}} containing your DNS servers. dhcpcd will prepend this file to the beginning of {{ic|/etc/resolv.conf}}. An example {{ic|/etc/resolv.conf.head}} for someone using [[OpenDNS]] would be: | Alternatively, you can create a file called {{ic|/etc/resolv.conf.head}} containing your DNS servers. dhcpcd will prepend this file to the beginning of {{ic|/etc/resolv.conf}}. An example {{ic|/etc/resolv.conf.head}} for someone using [[OpenDNS]] would be: | ||
| Line 27: | Line 34: | ||
If you are not pleased with the OpenDNS servers, you might try [https://developers.google.com/speed/public-dns/ Google's nameservers] as an alternative. | If you are not pleased with the OpenDNS servers, you might try [https://developers.google.com/speed/public-dns/ Google's nameservers] as an alternative. | ||
| + | |||
# Google nameservers | # Google nameservers | ||
nameserver 8.8.8.8 | nameserver 8.8.8.8 | ||
nameserver 8.8.4.4 | nameserver 8.8.4.4 | ||
| + | |||
| + | === Regenerate /etc/resolv.conf === | ||
| + | |||
| + | Required package: {{Pkg|openresolv}} | ||
| + | |||
| + | resolvconf -u | ||
=== Write-protect /etc/resolv.conf === | === Write-protect /etc/resolv.conf === | ||
Another way to protect your {{ic|/etc/resolv.conf}} from being modified by anything is setting the write-protection attribute: | Another way to protect your {{ic|/etc/resolv.conf}} from being modified by anything is setting the write-protection attribute: | ||
| + | |||
# chattr +i /etc/resolv.conf | # chattr +i /etc/resolv.conf | ||
| − | ===Use timeout option to reduce hostname lookup time=== | + | === Use timeout option to reduce hostname lookup time === |
| + | |||
If you are confronted with a very long hostname lookup (may it be in [[pacman]] or while browsing), it often helps to define a small timeout after which an alternative nameserver is used. To do so, create a file called {{ic|/etc/resolv.conf.tail}} and add the following line: | If you are confronted with a very long hostname lookup (may it be in [[pacman]] or while browsing), it often helps to define a small timeout after which an alternative nameserver is used. To do so, create a file called {{ic|/etc/resolv.conf.tail}} and add the following line: | ||
| + | |||
options timeout:1 | options timeout:1 | ||
Then restart your network daemon and see if it works better. | Then restart your network daemon and see if it works better. | ||
Revision as of 21:30, 4 October 2013
zh-CN:Resolv.conf From from the resolv.conf(5) man page:
- "The resolver is a set of routines in the C library that provide access to the Internet Domain Name System (DNS). The resolver configuration file contains information that is read by the resolver routines the first time they are invoked by a process. The file is designed to be human readable and contains a list of keywords with values that provide various types of resolver information.
- "On a normally configured system this file should not be necessary. The only name server to be queried will be on the local machine; the domain name is determined from the host name and the domain search path is constructed from the domain name."
Contents
Preserve DNS settings
dhcpcd, NetworkManager, and various other processes can overwrite /etc/resolv.conf. This is usually desirable behavior, but sometimes DNS settings need to be set manually (e.g. when using a static IP address). There are several ways to accomplish this. If you are using NetworkManager, see this thread on how to prevent it from overriding your /etc/resolv.conf.
Modify the dhcpcd Config
dhcpcd's configuration file may be edited to prevent the dhcpcd daemon from overwriting /etc/resolv.conf. To do this, add the following to the last section of /etc/dhcpcd.conf:
nohook resolv.conf
Note: If you use netctl and static IP address assignment, do not use the
DNS* options in your profile, otherwise resolvconf is called and /etc/resolv.conf overwritten.Use resolv.conf.head
Alternatively, you can create a file called /etc/resolv.conf.head containing your DNS servers. dhcpcd will prepend this file to the beginning of /etc/resolv.conf. An example /etc/resolv.conf.head for someone using OpenDNS would be:
# OpenDNS servers nameserver 208.67.222.222 nameserver 208.67.220.220
If you are not pleased with the OpenDNS servers, you might try Google's nameservers as an alternative.
# Google nameservers nameserver 8.8.8.8 nameserver 8.8.4.4
Regenerate /etc/resolv.conf
Required package: openresolv
resolvconf -u
Write-protect /etc/resolv.conf
Another way to protect your /etc/resolv.conf from being modified by anything is setting the write-protection attribute:
# chattr +i /etc/resolv.conf
Use timeout option to reduce hostname lookup time
If you are confronted with a very long hostname lookup (may it be in pacman or while browsing), it often helps to define a small timeout after which an alternative nameserver is used. To do so, create a file called /etc/resolv.conf.tail and add the following line:
options timeout:1
Then restart your network daemon and see if it works better.