Red Hat Summit5.5. Kernel parameters for DNS configuration
You can use kernel arguments to enable DNS over TLS (DoT) at boot time and set DNS resolution behavior for your system.
rd.net.dns-resolve-modeDefines how DNS servers from global configuration are used during resolution. The following modes are relevant for both kernel arguments and
NetworkManager.confglobal configuration:exclusive-
Uses only the DNS servers specified by kernel arguments or in
NetworkManager.conf. Forbids fallback to DNS servers retrieved from connections. This mode is currently relevant only fordnsconfdplugin. prefer- Forbids using DNS servers from connections for general queries unless the queries are subdomains of domains set by connection.
backup- Merges and uses DNS servers from both the global configuration and network connections for the same purposes.
rd.net.dns-serversConfigures the list of DNS servers to use. To define multiple DNS servers, set
rd.net.dnsmultiple times:rd.net.dns=dns+tls://<server_ip_1>#<dns_server_hostname_1> rd.net.dns=dns+tls://<server_ip_2>#<dns_server_hostname_2>For example:
rd.net.dns=dns+tls://198.51.100.143#dot.dns.example.com rd.net.dns=dns+tls://203.0.113.1#dot.dns.example.netrd.net.dns-backend-
Specifies the back-end DNS resolver. When set to
dnsconfd, the system usesdnsconfdas a local DNS cache configuration daemon.
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