App connectors handle DNS requests for app domains over PeerAPI,
but a safety check verifies the requesting peer has at least permission
to send traffic to 0.0.0.0:53 (or 2000:: for IPv6) before handling the DNS
request. The correct filter rules are synthesized by the coordination server
and sent down, but the address needs to be part of the 'local net' for the
filter package to even bother checking the filter rules, so we set them here.
See: https://github.com/tailscale/corp/issues/11961 for more information.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Updates: ENG-2405
3496d62ed3