DNS settings
While this section is not complicated, many networking problems can be traced back to DNS problems. Things to check in this area include:
• Are there values for both primary and secondary entries?
• Is the local domain name correct?
• Are you using IPv6 addressing? If so, are the IPv6 DNS settings correct?
• Are you using Dynamic DNS (DDNS)? If so, is it using the correct server, credentials, and interface?
• Can you contact both DNS servers to verify the servers are operational?
• If an interface addressing mode is set to DHCP and is set to override the internal DNS, is that interface receiving a valid DNS entry from the DHCP server? Is it a reasonable address and can it be contacted to verify it’s operational?
• Are there any DENY security policies that need to allow DNS?
• Can any internal device perform a successful traceroute to a location using the FQDN? See
Traceroute.