When we request Let’s Encrypt certificate, we encounter a problem like below on your server.

https://acme-v02.api.letsencrypt.org Let's Failed to connect to the encrypted server.
Please try again later or report the issue to support it.
Detail
Could not obtain directory: cURL error 7: Failed to connect to 2606:4700:60:0:f53d:5624:85c7:3a2c: Network is unreachable (see <http://curl.haxx.se/libcurl/c/libcurl-errors.html>)

If an error is received, chances are that on your ethernet card ipv6 is open and a default ipv6 is defined and the connection with the curl is not possible.

In this article, we will connect to our Centos server using the “Remote Desktop Connection” application on our computer without the help of any third-party program. We will learn how to do it by following the steps below.

1- The first step is to install Gnome Gui.

// yum group install "GNOME Desktop" "Graphical Administration Tools"

2- Let’s standardize our graphic display for the start.

// ln -sf /lib/systemd/system/runlevel5.target /etc/systemd/system/default.target

3- In this step, we reboot our server.

1) We select Start » Administrative Tools » Windows Firewall With Advanced Security.

Windows Firewall Width Advanced Security

2) In the window that opens, we right-click on Inbound Rule and say New Rule.

Inbound Rule

3) We choose the Custom option from Rule Type.

Rule Type

4) We click the Next button and proceed.

New Inbound Rule Wizard

Dealing with Lockups

DO IT:  As necessary.

If your computer “locks up” on you, you may want to take a look at your Task Manager.  Windows Task Manager is a cool tool that lets you see all the programs you currently have open and determine if any of them are “Not Responding” – or causing your computer to lock up.  If you have one or more programs that are Not Responding, you have the opportunity in Task Manager to end them safely.

Passwords

DO IT:  Monthly, or as necessary.

This is pretty simple.  Change your passwords and change ‘em often.

An easy way for you to protect your sensitive data and email is to change your passwords on a monthly basis or even more often depending on how frequently you use computers away from home.

If you log on to your email on any remote computer – such as at the library or in cyber cafes – then the possibility exists that the computer could have a key-stroking virus present.