Types of DNS records

  There are many types of DNS records, but the most common ones are:

    A record: An A record maps a hostname to an IPv4 address. This is the most common type of DNS record and is used to resolve hostnames to IP addresses.
    AAAA record: An AAAA record maps a hostname to an IPv6 address. This type of record is less common than A records, but it is becoming more important as IPv6 adoption increases.
    CNAME record: A CNAME record creates an alias for a hostname. This means that a CNAME record can be used to point to another hostname. CNAME records are often used to create redirects or to point to different hostnames for different purposes.
    NS record: An NS record specifies the name servers for a domain. Name servers are responsible for resolving hostnames to IP addresses.
    MX record: An MX record specifies the mail exchange servers for a domain. Mail exchange servers are responsible for delivering email to the domain.

There are many other types of DNS records, but these are the most common ones. DNS records are used to store information about domains and hostnames. This information is used by DNS servers to resolve hostnames to IP addresses and to deliver email.

Here are some additional DNS record types:

    PTR record: A PTR record provides a domain name in reverse-lookups. Reverse-lookups are used to find the domain name associated with an IP address.
    SRV record: A SRV record specifies a port for specific services. SRV records are used to find the IP address and port number of a service, such as a mail server or web server.
    TXT record: A TXT record allows you to store arbitrary text in a DNS record. TXT records are often used for security purposes, such as SPF and DKIM.

DNS records are an important part of the Domain Name System (DNS). The DNS is a hierarchical naming system for computers, services, or any resource connected to the internet or a private network. It associates various information with domain names assigned to each of the participants. Most prominently, it translates easily memorized domain names to the numerical IP addresses needed for locating and identifying computer services and devices with the underlying network protocols.

what is the different between thick and thin disk in vmware Or, thick-provisioned and thin-provisioned disks

what is the different between thick and thin disk in vmware Or,  thick-provisioned and thin-provisioned disks 

thick-provisioned disks are created with the entire size of the disk pre-allocated on physical storage at the time the disk is created. This pre-allocation means that creating a 50GB virtual disk actually consumes 50GB of physical disk space on your drives.

 thin-provisioned disks are created with the amount of physical disk storage used by a virtual disk is equal to the amount of actual data on that disk. If you create a 100GB disk but only use 20GB of that disk, the actual disk consumption on your physical drives will be 20GB.

Note: Versions of ESX prior to 4.0 were only capable of creating thick-provisioned disks.

network throughput test in windows and linux

Install iperf on Ubuntu

root# apt-cache search iperf

iperf - Internet Protocol bandwidth measuring tool

root#apt-get install iperf

Install iperf on RHEL & Fedora

root#yum search iperf

iperf.i686 : Measurement tool for TCP/UDP bandwidth performance

iperf3.i686 : Measurement tool for TCP/UDP bandwidth performance

yum install iperf3.i686

Install iperf for Windows

download iperf.exe and copy into C:\Documents and Settings\abc. abc is the logged-in user location.

iperf can be installed on two machines. You'll run one as a server, and one as a client. On the server side, run below. -s:Act as a Server, -c:Act as a client, -p:specify a port

Open Command prompt and run below commands.

On server side run below and press enter
iperf.exe -s
-------------------------------------
Server listening on TCP port 5001
TCP window size: 8.00 KByte (default)
-------------------------------------


On the client side, run:

iperf.exe -c [server_ip]
iperf.exe -c 192.168.xx.xx
--------------------------------------------------
Client connecting to 192.168.xx.xx, TCP port 5001
TCP window size: 65.0 KByte (default)
--------------------------------------------------
[  3] local 192.168.10.30 port 53345 connected with 192.168.xx.xx port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  37.9 MBytes  31.8 Mbits/sec

what is ssl

SSL (Secure Sockets Layer) is the standard security technology for establishing an encrypted link between a web server and a browser. This link ensures that all data passed between the web server and browsers remain private and integral. SSL is an industry standard.

What is the different between windows .msi and .msp file

An application that has been installed using the Microsoft Windows Installer can be upgraded by reinstalling an updated installation package (.msi file), or by applying a Windows Installer patch (an .msp file) to the application.

what is Hyper-Threading

Hyper-Threading technology is a technique which enables a single CPU to act like multiple CPU’s.

how to upgrade unbuntu kernel

Follow below steps to upgrade Ubuntu Kernel

#uname -a                                         #Check current Kernel version

#aptitude search linux-image              #Check which is the latest version

#aptitute install update

#aptitute install linux-iamge_***  -y

#reboot                                            #reboot the system to take effect the new change