- nmstate doesn't rollback dns options from nncp.
- search and server's values are rollbacked successfully, but options are not
deleted.
- Red Hat supports nmstate operator to config dns setting at Day2 instead of setting with nmcli in RHCOS directly.
- The function is unreliable, making it difficult for users to apply settings.

- Test version is "nmstate operator 4.14-202410241808"

- Apply a nncp with dns options and roll-back dns options from the nncp

1. Apply NodeNetworkConfigurationPolicy to set dns-resolver with dns options
~~~
apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
 name: worker-0-dns-testing
spec:
  nodeSelector:
    kubernetes.io/hostname: <target_node>
  desiredState:
    dns-resolver:
      config:
        search:
        - example.com
        - example.org
        server:
        - 2001:db8:f::1
        - 192.0.2.251
        options:               // set options
        - timeout:2
        - attempts:3
~~~
$oc debug node[node]
$chroot /host
$cat /etc/resolv.confsearch example.com example.org
nameserver 2001:db8:f::1
nameserver 192.0.2.251
options timeout:2 attempts:3      // option are applied

2.  delete options in NodeNetworkConfigurationPolicy
~~~
apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
 name: worker-0-dns-testing
spec:
  nodeSelector:
    kubernetes.io/hostname: <target_node>
  desiredState:
    dns-resolver:
      config:
        search:
        - example.com
        - example.org
        server:
        - 2001:db8:f::1
        - 192.0.2.251
~~~     
$oc debug node[node]
$chroot /host
$cat /etc/resolv.conf
search example.com example.org
nameserver 2001:db8:f::1
nameserver 192.0.2.251
options timeout:2 attempts:3     // theses options are not deleted.

search and server's values are rollbacked successfully, but options are not.     

options still remain
$cat /etc/resolv.conf
search example.com example.org 
nameserver 2001:db8:f::1 
nameserver 192.0.2.251 
options timeout:2 attempts:3     // theses options are not deleted.    

options are deleted from /etc/resolv.conf
$cat /etc/resolv.conf
search example.com example.org 
nameserver 2001:db8:f::1 
nameserver 192.0.2.251 

Support for DNS options was added in nmstate.
https://access.redhat.com/solutions/7048779