Update a command in AWS instances (using ansible & ssh-agent)?
1) First, we need to start the ssh-agent (this program holds private keys for public key authentication) using the command.ssh-agent bash2) Now, we need to add the private key, along…
About PermitRootLogin and PasswordAuthentication in the sshd_config file?
PermitRootLogin: The PermitRootLogin options solely determine whether direct login as the root user via SSH to the server is permissible. The valid arguments for this directive are: no, yes, forced-commands-only,…
HOW TO MEASURE NETWORK SPEED BETWEEN SERVERS IN LINUX?
On receiving server B: madhu@192.168.1.100:~$ while true; do netcat -vvlnp 5656 > /dev/null; doneListening on [0.0.0.0] (family 0, port 5656)Connection from [192.168.1.100] port 5656 [tcp/*] accepted (family 2, sport 53714)Listening…
How do you upgrade vCenter appliance 6.7 to 7.0?
1) Download the vCSA 7.0 ISO and mount it on any Windows system. 2) Once the ISO is mounted, navigate to 'vcsa-ui-installer' -> 'win32,' double-click 'installer.exe,' and select 'Upgrade.' 3)…
why do we need to use nice and ionice?
Schedule the Linux process CPU priority with nice? By default, every process is assigned the same CPU scheduling priority level. Consequently, the kernel strives to allocate a fair amount of…
What’s the difference between ENTRYPOINT and CMD in a Dockerfile?
About CMD: The Docker CMD defines the default executable of a Docker image. The CMD instruction is used only when no arguments are added to the run command while starting…
Why do we need an SRV DNS record?
For explanation purposes, let's consider a practical example involving an LDAP server and a client. Usually, when configuring an LDAP client, we specify the direct address—either the LDAP server's IP…
Adding SPF record to the domain for successful email delivery
If your company is using the paid version of Gmail for business and wants to have email IDs in the format of username@companydomain.com, then you need to add the 'SPF'…
4 reasons why email’s go to SPAM?
Are your emails going to the spam folder? Customers are complaining that they have not received your emails, and some have mentioned that although they received the email, it ended…
Why is SPF important for email delivery?
The Sender Policy Framework (SPF) Record is created to prevent applications or users that you don't trust from sending emails on behalf of your domain. Mail delivery process with SPF…