Explore information related to firewall

Enable FirewallD logging for denied packets on Linux

This article will guide you on how to enable #FirewallD logging for denied packets on #Linux. It is an important task to keep an eye on the rejected and dropped packets using FirewallD for #Linux system administrators. 

To enable logging option you need to use #LOG iptables/kernel module. It turn on kernel logging of matching packets. When this option is set for a rule, the Linux kernel will print some information on all matching packets (like most IP header fields) via the kernel log.

To log a dropped packet in iptables:

1. iptables -N LOGGING: Create a new chain called LOGGING.

2. iptables -A INPUT -j LOGGING: All the remaining incoming packets will jump to the LOGGING chain.

3. line#3: Log the incoming packets to syslog (/var/log/messages).

To  restart iptables:

i. To start firewall from a shell enter: # chkconfig iptables on. # service iptables start.

ii. To stop firewall, enter: # service iptables stop.

iii. To restart #firewall, enter: # service iptables restart.

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Install Firejail in Linux

This article will guide you on steps to #install #Firejail in Linux. Basically, Firejail reduces the risk of security breaches by restricting the untrusted applications and separating them from other parts of the system. 

#Sandboxing involves providing a safe environment for a program or #software so that you can play around with it without hurting your system. It actually keeps your program isolated from the rest of the system, by using any one of the different methods available in the #Linux #kernel.

To Install the Firejail Software:

1. Open up a terminal window.

2. Issue the command sudo apt-get install firejail.

3. Type your sudo password and hit Enter.

4. If prompted, type y to allow the installation to continue.

5. Allow the installation to complete.

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Frequent connection timeout errors due to cPanel firewall issues

Make sure that your browser is up to date. Sometimes the “Connection timed out” message can appear if your browser is out of date. Outdated #software can have compatibility issues and bugs that can cause this and other errors to appear. 

The HyperText Transfer Protocol (HTTP) 408 #Request Timeout response status code means that the server would like to shut down this unused connection. It is sent on an idle connection by some #servers, even without any previous request by the client.

To fix the problem, be sure that your browser is up to date.

To Fix the ERR_CONNECTION_TIMED_OUT Error:

1. Check Your Connection. Google Chrome, Firefox, and Edge all recommend that you should check your network connection.

2. Disable Firewall and Antivirus Software Temporarily. Firewalls and antivirus software are intended to protect users and their systems.

3. Disable Proxy Settings.

4. Change DNS Servers.

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Using CSF firewall to block countries

This article will guide you on how to block/allow countries in the CSF #firewall. CSF is used to restrict or allow countrywide IP ranges in the server using the country codes. For every country you want to deny, you just enter those letters in the field (separated by a comma). Once you're done, scroll to the bottom of the page and click CHANGE. This will restart the firewall, and you're now all set to go.

ConfigServe Firewall (#CSF) is a firewall configuration script created to provide better security for your server while giving you an easy to use and advanced interface for managing your #firewall settings in cPanel servers.

To limit the ability to connect on a specific port or ports to visitors with IP addresses originating in a specific country or countries, you must:

1. close the ports in the firewall.

2. define the country code allowed to connect on those blocked ports.

3. specify the blocked #ports to be opened for the specified country.

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Shorewall forward reject How to resolve this error

The 'Shorewall forward reject' error mainly occurs when there is any misconfiguration or missing in the rules added to the Shorewall configuration files. 

Shorewall rules file:

Entries in this file govern connection establishment by defining exceptions to the policies laid out in shorewall-policy(5). By default, subsequent requests and responses are automatically allowed using connection tracking. 

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Enable firewalld in Centos 7 How to do it

This article will guide you on steps to enable firewalld on #centos 7 servers for our customers. The firewall is one of the most important features of webservers. The #firewalld supports both IPv4 and IPv6 #firewall #settings.

Never run the iptables service and FirewallD service at the same time! The #iptables service is now provided by a separate package called iptables-services: Stop and disable the firewalld service first. # systemctl stop firewalld.

The firewalld daemon manages groups of #rules using entities called "zones". Zones are basically sets of rules dictating what traffic should be allowed depending on the level of trust you have in the networks your #computer is connected to.

To use FirewallD:

1. Installing and Managing FirewallD.

2. To start the service and enable FirewallD on boot: sudo systemctl start firewalld sudo systemctl enable firewalld.

3. Check the firewall status.

4. To view the status of the FirewallD daemon: sudo systemctl status firewalld.

5. To reload a FirewallD configuration: sudo firewall-cmd --reload.

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FileZilla connection closed by server

This article will guide you on how to resolve #FileZilla connection closed by #server. Also we discussed about the causes for the FileZilla connection getting closed by the server.

If your computer cannot connect to that server, then either your FTP software is not working correctly, or something on your #computer (probably a #firewall or other security software) is blocking all #FTP connections. You may want to try using other FTP software such as the free FileZilla.

In general, connection refused #errors are generated during a connect system call when an application attempts to connect using #TCP to a server port which is not open.

To fix FTP Connection refused error:

1. Make sure ftp server installed. Make sure ftp server installed and service is running.

2. Is ftp server running (is port 21 open)? Login to ftp server using ssh and try to telnet port 21 (to see port is open or not).

3. FTP user permissions.

4. Security or Firewall.

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Create a DigitalOcean Space and API Key

This article will guide you on the steps to create #DigitalOcean #Space and #API Key. You will also see the #server #URL, bucket name (or Space name), access key, and secret. With this information you can connect most any S3-compatible client or library to your new DigitalOcean Space!

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How To use Systemd to Sandbox Processes On Ubuntu 20 04

This article will guide you how to #Sandbox #Processes on Ubuntu 20.04 with Systemd for Lighttpd using different methods. Here we made the #lighttpd program more secure by using the #systemd sandboxing options. You can use these techniques with any process that systemd manages allowing you to continue to improve the #security of your system.

#Sandboxing is designed to prevent #threats from getting on the #network and is frequently used to inspect untested or untrusted code.

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Send Syslog with SSL TLS to Nagios Log Server

This article will guide you on how to Send #Syslog with #SSL / #TLS to Nagios Log Server by encryption which ensures that the #traffic between the #Linux machine and Nagios Log Server is not sent in plain text.

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Migrate data from Amazon S3 to DigitalOcean Spaces with rclone

This article will guide you on the steps to perform migration of data from #amazon #s3 to #DigitalOcean spaces. #Migration of #data is the primary task which #Website Administrators use for shifting from one object #storage service to another.

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VPN Error 806 Steps to fix it

This article will guide you on the steps to resolve #VPN #error 806 which occurs when the connection between our #Windows #computer and the VPN server has been established but the VPN remains incomplete. 

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Blocking IP Addresses Using Windows Firewall

This article will guide you on the steps to block the IP in the Windows firewall.

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Zimbra firewall configuration with UFW and firewalld How to set it up

This article will help you to configure Zimbra firewalls with UFW and firewalld.

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Firewall protection for Servers

This article shows the importance of Firewall to a system and Operating system to safeguard it against intruders and attacks.

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Configuring messenger csf

This article will show you how to set up CSF Messenger via command line.

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Solve curl 52 empty reply from server

Curl is the command line tool which is responsible for running curl through a Server shell. curl runs under the libcurl library which relays response from the server whenever a request is called.

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