Easy! IT | Server | HINFO record

Everything might be not exactly correct in this article but it’s very useful for beginners to understand IT terms. If you want to learn IT but you don’t have any experience to work in the IT industry, I wish it helps you to understand IT and you like to study IT more.

Let’s start our 3 minutes lesson!

What is a HINFO record?

HINFO record is written in a zone file.
HINFO record specifies the host information such as OS and CPU.
HINFO record is not used recently because of security reasons.

I suggest you read the following articles before you read this article if you don’t know DNS well.

DNS: IT Learning | Network | DNS | Japan Teams

Secondary DNS: IT Learning | Server | Secondary DNS | Japan Teams

1. HINFO records are used by Authoritative name server

HINFO record is a resource record in the Domain Name System (DNS). It’s written in a zone file.

There are two DNS servers. One is “Authoritative name server”. Another is called Caching DNS Server. Laptops usually ask Mr Caching DNS server the first question. If he can’t answer the question, he will ask Ms Authoritative name server.

Authoritative name server: IT Learning | Server | Authoritative name server | Japan Teams

**Mr Caching asks Ms Authoritative when he doesn’t have information in his cheat sheet.**

When Ms Authoritative receives the question from Mr Caching, she checks her job handbook called “Zone file”. There is much information in a zone file, and one of the information is “HINFO record”.

Zone file: IT Learning | Server | Zone file | Japan Teams

**Ms Authoritative checks her zone file when she answers the question from Ms. caching DNS.**

2. How to write HINFO records?

HINFO records specify the hardware type and Operating System (OS) in use at a host. The basic format in BIND is here,

Host Label TTL IN HINFO “Hardware(CPU)” “OS”

And a simple example is here,

big 180 IN HINFO “INTEL-486” “Windows”

In this case, a Host Label is “big”, which is a hostname of the domain in the zone file, like “big.meat.com.”. And 180 is seconds of TTL, which is Time To Live. This value specifies how long a resolver is supposed to cache or remember the DNS query. HINFO after IN means that this is a HINFO record. “INTEL-486” and “Windows” are the information of the target server, which is big.meat.com in this sample.

3. For what HINFO records are used?

HINFO records can be used by application protocols such as FTP, which uses special procedures when communicating with computers of a known CPU and OS type. But this record is not often used because of security reasons. So it’s usually used for internal systems, but you will not see this record often.