56 lines
1.8 KiB
Text
56 lines
1.8 KiB
Text
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[[!meta title="Setting static nameserver and search path with dhcpcd"]]
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If you're changing networks a lot, but want to keep a some static
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settings, this is **one** way to do it.
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## Motivation
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As most wireless networks are featured with unreliable and slow connections,
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I'm running my own (caching only) dns server on my notebook, to keep the
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answers in my local cache. Thus I always want to have
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nameserver 127.0.0.1
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as the first entry in my ***resolv.conf***.
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Additionally, I always want to have **schottelius.org** and **ethz.ch**
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in my search path, resulting in
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search schottelius.org ethz.ch
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Thus I am always able to type only the hostname, independent of my location.
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## Implementation
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I am currently using [dhcpcd](http://roy.marples.name/projects/dhcpcd/),
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which is shipped with [archlinux](http://www.archlinux.org/) by default.
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The package contains **/usr/lib/dhcpcd/dhcpcd-hooks/20-resolv.conf**,
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which takes ***/etc/resolv.conf.head*** and ***/etc/resolv.conf.tail***
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into account.
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According to **resolv.conf(5)**, if multiple nameservers are specified,
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they will be asked in the order listed, so
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echo nameserver 127.0.0.1 > /etc/resolv.conf.head
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ensures that my local nameserver is asked firstly. As the **domain** and
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**search** field override each other, the last entry wins:
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echo search schottelius.org ethz.ch > /etc/resolv.conf.tail
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## Further information
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The same can easily be done with other modular dhcp-clients, like udhcpc
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(part of [busybox](http://www.busybox.net/)).
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The behaviour of your resolver library may be different, be sure to
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check your local system documentation.
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There are a lot of small caching nameservers available. I have good
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experiences with [dnscache](http://cr.yp.to/djbdns/dnscache.html),
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[dnsmasq](http://www.thekelleys.org.uk/dnsmasq/) and
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[unbound](http://www.unbound.net/).
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[[!tag net sysadmin unix]]
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