tree a01ef32518e8441a7df92e38535706e0b7142e5b
parent 3d5873bc39b8e18c733aac78b0e0c94012954515
author Manojkiran Eda <manojkiran.eda@gmail.com> 1587051175 +0530
committer Brad Bishop <bradleyb@fuzziesquirrel.com> 1588020407 +0000

Override the fallbackDNS property

- fallbackDNS is a space-separated list of IPv4 and IPv6
  addresses to use as the fallback DNS servers. Any per-link
  DNS servers obtained from systemd-networkd.service take
  precedence over this setting, as do any servers set via
  DNS= above or /etc/resolv.conf.

- This setting is hence only used if no other DNS server
  information is known. If this option is not given, a
  compiled-in list of DNS servers is used instead.

- The default compiled list of DNS for systemd-resolved are
  ['1.1.1.1', '8.8.8.8', '1.0.0.1', '8.8.4.4',
   '2606:4700:4700::1111','2001:4860:4860::8888',
   '2606:4700:4700::1001', '2001:4860:4860::8844']
   which are google DNS servers.

 - The problem with this is that, when there is no DNS configuration
   on BMC(or the customer removes it),resovld would still used the
   precompiled compiled list of google DNS for quires without the
   user knowledge(security issue)

 - This commit would override the fallbackDNS to NULL

Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
Change-Id: Ibbc54bead1941436b09a2555f3b7aefcd552ee0d