Open-source firewall OS

Open-source firewall OS

A firewall OS is a specialized operating system designed to run on dedicated hardware, offering advanced tools to control and monitor network traffic. It enforces security policies, supports VPNs and intrusion detection, and is highly customizable for specific needs

Here are a list of open-source firewall OS ๐Ÿ‘‡

Find pdf books with all my Linux and cybersecurity related infographics at https://study-notes.org

graphical user interface, application

Windows 11 Installation Bypassing the Microsoft Account

New Trick in Windows 11 Installation: Bypassing the Microsoft Account Requirement

For IT professionals, sysadmins, and power users โ€” hereโ€™s a useful Windows 11 installation tip.

Microsoft recently removed the hashtag
hashtagBypassNRO.cmd script from Windows 11 preview builds, which previously made it easier to bypass the Microsoft Account (MSA) requirement during setup.

While registry tweaks still technically work, they now require more manual input.

But a new, much simpler workaround has surfaced:

Steps to bypass the Microsoft Account requirement during setup:

1. When you reach the โ€œLetโ€™s connect you to a networkโ€ screen, press Shift + F10 to open the Command Prompt.
2. Type: start ms-cxh:localonly
3. Hit Enter โ€” this forces Windows into a local account setup flow, bypassing the MSA prompt entirely.

This method, discovered by X user Wither OrNot and verified by BleepingComputer, provides a more streamlined way to install Windows 11 with a local user account.

Great little trick for clean installs

Note:
โ€ข This method is confirmed to work on Windows 11 22H2 and later.
โ€ข Future updates may disable this workaround.
โ€ข Not recommended for managed work or school devices, as organizational policies may block or restrict local account setups.

Disclaimer:
This information is intended strictly for legitimate and educational purposes โ€” such as setting up personal devices or regaining access to your own system. Always respect software terms of use and organizational IT policies.

graphical user interface

Network Address Translation

๐Ÿ”น Understanding NAT (Network Address Translation): The Optimal Solution for IPv4 Address Exhaustion ๐Ÿ”น
In todayโ€™s fast-growing networking world, NAT (Network Address Translation) stands as one of the key technologies that helped keep the internet running the way we know it. Here’s a quick breakdown of what Iโ€™ve learned during my CCNA journey:
๐Ÿ’ก What exactly does NAT do?
It allows multiple devices on a local network to access the internet using a single public IP address.
Think of it as a translator between the internal language of your network and the global internet.
๐Ÿ”ธ Types of NAT:
1๏ธโƒฃ Static NAT โ€“ One-to-one mapping. Perfect for public servers.
2๏ธโƒฃ Dynamic NAT โ€“ Assigns a public IP from a pool when needed.
3๏ธโƒฃ PAT (Port Address Translation) โ€“ Most common! Uses one public IP and distinguishes devices by port numbers.
๐Ÿ” Why Use NAT?
โœ… Saves limited IPv4 addresses
โœ… Adds a layer of security
โœ… Makes switching ISPs easier
โœ… Simplifies routing inside private networks
๐Ÿ“Œ Did you know?
Without NAT, we wouldโ€™ve run out of IPv4 addresses a long time ago. It bought us valuable time before the full shift to IPv6.
๐Ÿš€ Challenge:
How would you configure Static NAT for a web server on a Cisco router?
Share your thoughts or real-world examples in the comments ๐Ÿ‘‡
hashtagNetworking hashtagCCNA hashtagNAT hashtagIPv4 hashtagCisco hashtagNetworkTips hashtagTechCommunity

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MikroTik Router Auto Backup via Email

MikroTik Routerย is popularly used not only in ISP network but also in enterprise office network. So, MikroTik is a popular item to network administrator. A regular task of a network administrator is to keep and store router configuration file backup.

Almost every network administrator takes configuration file backup manually. But MikroTik Router has an E-mail tool by which network administrators can automate configuration file backup regularly via email and can reduce his daily manual task easily.

E-mail toolย is not configured by default in MikroTik RouterOS. So, network administrators must configure E-mail tool as well as do some scripting for getting email backup service. In this article, we are going to see how to configure MikroTik E-mail tool to get configuration file backup via email with a few steps.

mikrotik-mail-backup

MikroTik Router Automated Email Backup Configuration

We will now configure MikroTik E-mail tool so that it can send configuration file backup via email. Complete configuration for storing backup and then sending via email can be divided into 3 steps.

  1. Email configuration
  2. Writing script for storing backup and sending Email
  3. Creating scheduler for executing script regularly

Step 1: MikroTik Router Email Configuration

For sending email from MikroTik RouterOS, we first need to configure sender email. MikroTik does not have a SMTP Server. For this, we have to provide SMTP server as well as email username and password so that MikroTik RouterOS can send mail through that SMTP Server.

So, to setup SMTP Server and email username and password in MikroTik RouterOS, follow the below steps carefully.

  • Go to Tools > Email and provide sender email information as below:
    Server: SMTP Server IP address (Use your mail server IP or try using Gmail IP: 173.194.77.108)
    Port: SMTP Server Port (usually 25 or if you use Gmail SMTP, use 587)
    From: Put your email address which will indicate from address for the mail.
    User: Put email user name (first part ofย @ย sign) or full email address if applicable.
    Password: Put the email password.
  • Alternatively, we can do cmd:/tool e-mail
    set address=173.194.77.108
    set port=587
    set from=systemzonedotnet@gmail.com
    set user= systemzonedotnet
    set password=*******
    Where 173.194.77.108 is Gmail SMTP Server IP, systemzonedotnet@gmail.com is a test mail ID created for this article and โ€œ*******โ€ is the password.
  • For checking email configuration, send a test mail from MikroTik with below cmd:/tool e-mail send to=sezan.sayeed@yahoo.com subject=โ€email testโ€ body=โ€email testโ€ tls=yes

If everything is OK, the test email will be sent to the receiver email address. We will now write script for storing backup file and sending via mail.

Step 2: Script for Storing Backup File and Sending via Email

After completing email configuration, we will now write a script that will store backup file and then send the backup file to the desired mail address. Follow below steps to write script in MikroTik RouterOS.

  • Go to System > Scripts and click on PLUS SIGN (+) to add a new script. New Script window will appear.
  • Type a script name (for example, Mail Backup) in Name input field and then copy and paste the below code in source box.
    :log info โ€œMikrotik Backup JOB Started . . . โ€œ
    :global backupfile configbackup
    :log info โ€œDeleting old Backup File If available otherwise ignore & process further . . . โ€œ
    /system backup save name=$backupfile
    :log info โ€œBackup process pausing for 10s so it complete creating backup fileโ€
    :delay 10s
    :log info โ€œStart Sending Backup File via Email using GMAIL SMTPย  . . .โ€ tool e-mailsend to=sezan.sayeed@yahoo.com subject=([/system clock get date] . \ โ€ MikroTik Backupโ€) body=โ€MikroTik email Backupโ€ tls=yes file=$backupfile
    :delay 40s
    :log info โ€œBackup Finishedโ€
    :log info โ€œDeleting Backup File. All Done.โ€
    /file remove $backupfile
  • Now click Apply and OK button for saving this script.
  • You can run this script manually by clicking Run Script button or typing this cmd: >ย system script run 0ย 

Script for storing configuration file backup and sending the file via email is now ready. We will now create a scheduler so that this script can be run regularly at a fixed time.

Step 3: Scheduler for Executing Script Regularly

We have created script for storing configuration file and sending via mail. But the script cannot execute itself. So, we have to create a scheduler that will execute the above script regularly at our desired time. For creating a scheduler in MikroTik RouterOS, follow below steps.

  • Go to System > Schedulerย and click on PLUS SIGN (+) to add new scheduler.
  • Type scheduler name inย Nameย input box and put script executing time inย Start Time input box. For example, if you want to execute the script at 5:30 PM, put the time as 17:30:00.
  • Put sending time interval at Intervalย input field. For example, if you want to execute the script daily, put the value as 24:00:00
  • Now put your script name that you have provided at step 2(here, Mail Backup) in On Event box and then click Apply and OK button.

Scheduler is now ready. If everything is OK, MikroTik Router will send a mail regularly to the desired email address where configuration file should have attached.

You should follow above steps one by one otherwise your desired result may not come. If you face difficulty to do above steps properly, please watch the video tutorial carefully aboutย MikroTik Router Auto Backup via Email. I hope, it will reduce your confusion.

Note:ย This configuration has been done inย MikroTik Router OS version 5.20. If you face any problem in upgraded version, please let me know. I will try to solve the problem.

MikroTik Router configuration file backup via emailย has been discussed in this article. I hope, you will now be able to configure MikroTik Router for sending configuration file backup via email. If you face any problem, feel free to discuss in comment or contact me fromย Contactย page. I will try my best to stay with you.

๐–๐ก๐š๐ญ ๐ข๐ฌ ๐•๐‹๐€๐?

VLAN (๐‘‰๐‘–๐‘Ÿ๐‘ก๐‘ข๐‘Ž๐‘™ ๐ฟ๐‘œ๐‘๐‘Ž๐‘™ ๐ด๐‘Ÿ๐‘’๐‘Ž ๐‘๐‘’๐‘ก๐‘ค๐‘œ๐‘Ÿ๐‘˜) is a basic networking technology that allows us to logically separate devices within a single physical network. Think of it as creating multiple virtual networks on one switch, giving you control over performance, security, and network managementโ€”all without the need for additional hardware.

๐–๐ก๐ฒ ๐ฌ๐ก๐จ๐ฎ๐ฅ๐ ๐ฒ๐จ๐ฎ ๐œ๐š๐ซ๐ž ๐š๐›๐จ๐ฎ๐ญ ๐•๐‹๐€๐?
In today’s fast-paced tech landscape, VLANs are essential for optimizing network performance and flexibility. Whether you’re in a business, educational institution, or a data center, VLANs provide benefits that can transform your network.

๐‡๐ž๐ซ๐ž ๐š๐ซ๐ž ๐ญ๐ก๐ž ๐›๐ž๐ง๐ž๐Ÿ๐ข๐ญ๐ฌ ๐จ๐Ÿ ๐•๐‹๐€๐:
1) Network Segmentation
VLANs enable logical separation of devices based on functions, departments, or needs. For example, you can set up VLANs for Staff, IT department, and guests to ensure separation and better control.

ARP (Address Resolution Protocol)

ARP maps a Layer 3 IP address to an Unknown Layer 2 MAC address, which is key for Nic-to-Nic communication at the data link layer.

Here’s a quick overview:

1. PC1 needs PC3’s MAC and IP address to communicate.
2. The IP can be static or assigned dynamically via DHCP.
3. To test connectivity, John use PC1 to ping PC3 in the same LAN.

How it works:
– PC1 sends an ARP request to resolve PC3’s MAC address.
– The ARP request is broadcast, with unknown destination MAC set to all F’s.
– PC3 replies with its MAC address with an ARP reply, allowing PC1 to send the ICMP request to eventually get an ICMP reply from PC3.

Understanding ARP is key to knowing how data moves through a network for effective communication and to troubleshoot various issues.

Animation credit: NetworkAcademy.IO