Externally Monitoring DNS Servers
eG Enterprise offers the DNS server or the Windows DNS server model (discussed previously), which not only checks how well the DNS server performs host name resolutions, but also indicates how healthy the DNS server host is by reporting a wide variety of operating system-level metrics. However, some administrators might not have access to the DNS server for installing agents. To enable such administrators to deploy an eG agent on a remote host to monitor just the availability of the DNS server, and determine how quickly the server can resolve a host name to an IP address or vice-versa, eG Enterprise offers an External DNS server model (see Figure 3).
The DNS Service layer of this model uses an external agent to execute a Dns test, which emulates a user request to the DNS server to ascertain its availability and responsiveness. The Network test associated with the Network layer performs periodic network health checks.