OES DNS server is a distributed database system that provides hostname-to-IP resource mapping (usually the IP address) and other information for computers on a network. If for some reason the OES DNS server is not accessible, clients lose their ability to connect to the network because DNS lookups will fail. This is possible because the DNS server is automatically started, stopped, and restarted on different servers in the cluster by OES Cluster Services. You can prevent this problem by configuring DNS with OES Cluster Services, which ensures that name resolution required by users to connect to the network is highly available.
Before you attempt to implement this solution, familiarize yourself with how Cluster Services works. For information, see the OES 2018 SP2: OES Cluster Services for Linux Administration Guide.