Network Monitoring Software - Name Server Lookup - PingCOPA
The PingCOPA network monitoring software provides a full NS Lookup command which can give you various DNS information for a domain.
You may use the default name server for the machine on which the PingCOPA network monitoring software is running, but this will probably be (or accessing) a caching Name Server: ISPs usually provide a Domain Name Server for customers. When this server is asked for the IP Address for a name, it will look it up, provide the result and keep a copy (cache) the information it received. Each DNS record has a TTL (Time To Live) which is the number of seconds that this should be trusted from the time it was given. This allows for changes to be made, eg moving a web site to another server because work is required on the original hardware. The TTL will usually be long for information which isn't likely to change often, but shorter for information that might change frequently.
However, this means that the information you receive may be out of date if, for example, some change was made during a long TTL. So information not from the defined DNS for the domain is Non-authoritative. If you wish to be completely sure about the information, first use the PingCOPA network monitoring software NS Lookup command to find the Authoritative Name Server for the domain, then enter that into the Name Server box and use this to request whatever records you require.
Select NS (Authoritative Name Server) in the Type box, and pingcopa.com in the Domain box, and Lookup using your default name server.
The PingCOPA network monitoring software will show (amongst other things) that the authoritative name server is ns1.intervations.com (IP Address: 184.108.40.206).
Uncheck the use default name server box, and enter 220.127.116.11 in the Name Server box.
Press the NS Lookup button and you will receive the authoritative information from the InterVations Name Server.
A - The IP Address of the domain or machine (eg www.intervations.com)
NS - The authoritative name server for this domain.
CNAME - One machine can have several names. A number of CNAMES (Canonical Names) can point to the same machine. eg smtp.mydomain.com and pop.mydomain.com can both point to mail.mydomain.com
SOA - The Start Of Authority because it denotes the DNS entry as the official source of information for its domain, and lists this information.
PTR - Domain Name Pointer. Enables a reverse lookup, eg looking up the IP address will reveal the name of the machine.
MX - The machine that accepts mail for this domain.
TXT - A text record used for general purposes, eg Sender Policy Framework
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