How do I override Linode DNS servers for local cacheing bind9?
On an Ubuntu 18 linode, I'm using postfix (with Zimbra) and need to have all DNS queries made to the local bind9 cacheing DNS.
systemd-resolve shows link eth0 being served by 173.255.241.. etc.
I've tried putting "supersede domain-name-servers 127.0.0.1;" in /etc/dhcp/dhclient.conf
I've tried editing /etc/systemd/network/05-eth0.network to specify DNS=
I know better than to edit /etc/resolv.conf
It seems like it's hitting 127.0.0.1 for most queries, but not all, and uribl rejects queries coming from the Linode DNS.
1 Reply
Just to elaborate, I am hitting the local DNS instance, after adding DNS=127.0.0.1 to /etc/systemd/network/05-eth0.network, but the Linode resolvers are 2nd and 3rd in the list:
Link 2 (eth0)
Current Scopes: DNS
LLMNR setting: yes
MulticastDNS setting: no
DNSSEC setting: no
DNSSEC supported: no
DNS Servers: 127.0.0.1
173.255.241.5
173.255.243.5
173.255.244.5
DNS Domain: members.linode.com
If postfix hits uribl using one of the linode DNS servers, the query is rejected and the mail is bounced.
This is the interface config /etc/systemd/network/05-eth0.network. If I take out the DHCP line, the network doesn't come up (needed a trip to rescue mode).
mojo@mail:~$ cat /etc/systemd/network/05-eth0.network
[Match]
Name=eth0
[Network]
DHCP=ipv4
DNS=127.0.0.1
Domains=members.linode.com
IPv6PrivacyExtensions=false