DNS
From ServersCheck Wiki
Description
The new DNS check (release 7.1.0) enables users to monitor their DNS servers or their domain names. The DNS check will perform a reverse DNS lookup by checking the IP address for a given domain name.
The check can perform a lookup of following record types: A, MX, CNAME, RTP and NS: Address (A) records direct a hostname to a numerical IP address.
CNAME allows a machine to be known by one or more hostnames. There must always be an A record first, and this is known as the canonical or official name.
NS records specify the authoritative nameservers for the domain
MX (Mail eXchanger) records specify the mail servers which handle mail for the domain
PTR record maps an IPv4 address to the canonical name for that host
How to perform a DNS check
First create a new rule like explained step by step in following help file article: Define Rules
IP Address is the IP you expect to be returned by the DNS server. Domain name is the domain name to validate. Record Type for the lookup: A, CNAME, MX, NS or PTR DNS Server to be used for the reverse lookup. If left blank or set to default then it will use the default name server. Otherwise specify the DNS server you would like to use for the lookup.
Click on Test Settings to try out the check you defined.
