dnsmasq list-servers “precedence”

I have a device, in a LAN, behind a router, that runs a linux and need to provide it with an internal DNS server, to resolve names for its own internal applications (it's OpenWRT-based).

The reason to do this is that for some queries, the DHCP-provided stuff doesn't seem to work as expected and some of the client apps get a timeout (sorry for the lack of details, but I'm pretty sure about this as wireshark captures prove some DNS queries are not correctly responded).

I don't intend to run a DHCP server in this device, just local DNS server.

I have a basic knowledge about DHCP, DNS and their handshakings, and I'm not sure how this scenario works with dnsmasq: I configured the DNS server -in the device- with an external public nameserver in its list of servers, expecting (maybe wrongly, I don't know) for it to override the nameservers provided by the DHCP/router/ISP (being the device a DHCP client in this case).

The /etc/resolv.conf file just has the nameserver 127.0.0.1 line, and everything seems to work as I expect.

But what happens if any external DNS is down? Will it fallback to that provided by the DHCP handshaking?

I think put in other words the question would be: when dnsmasq has a list of servers, will it use the DHCP DNS settings?

Hope this is clear.

0
задан 12 April 2018 в 01:51
1 ответ

Из того, что я мог видеть, похоже, что dnsmasq работает следующим образом:

  • он ставит себя в качестве DNS-сервера для использования в обычном файле resolv (например, в моей установке OpenWRT это /tmp/resolv.conf );
  • он начинается с опции для установки файла resolv ( - resolv-file , указывая на /tmp/resolv.conf.auto в OpenWRT) для внутреннего использования, где настраиваемые серверы имен и , предоставляемые DHCP-сервером, указаны в списке.

Итак, короче говоря, он отслеживает все серверы имен.

0
ответ дан 5 December 2019 в 06:14

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