The objective of this task was to configure Windows Defender Firewall by creating and testing a basic inbound firewall rule to block network traffic on TCP Port 23 (Telnet). After testing, the rule was removed to restore the original firewall configuration.
- Windows Defender Firewall with Advanced Security
- Windows 11
- GitHub
Opened Windows Defender Firewall with Advanced Security using the Run dialog.
wf.msc
Reviewed the existing Inbound Rules to understand the current firewall configuration.
Created a new firewall rule with the following configuration:
| Setting | Value |
|---|---|
| Rule Type | Port |
| Protocol | TCP |
| Port Number | 23 |
| Action | Block the Connection |
| Profiles | Domain, Private, Public |
| Rule Name | Block Telnet Port 23 |
Verified that the Block Telnet Port 23 rule appeared successfully under Inbound Rules.
Deleted the firewall rule after testing to restore the original configuration.
Port 23 is used by the Telnet protocol. Telnet transmits usernames, passwords, and other sensitive information in plain text without encryption, making it vulnerable to interception. Blocking this port helps prevent insecure remote access.
A firewall monitors incoming and outgoing network traffic and applies predefined security rules to allow or block connections based on ports, protocols, applications, IP addresses, and connection states.
A firewall is a network security system that monitors and filters incoming and outgoing network traffic according to predefined security rules.
A stateful firewall tracks active network connections and makes filtering decisions based on the connection state.
A stateless firewall evaluates each packet independently without maintaining connection information.
- Inbound Rules: Control incoming network traffic.
- Outbound Rules: Control outgoing network traffic.
UFW (Uncomplicated Firewall) provides a simplified command-line interface for managing Linux firewall rules without requiring complex iptables commands.
Telnet does not encrypt transmitted data, making usernames and passwords vulnerable to interception. Blocking Port 23 improves system security.
- Leaving unnecessary ports open
- Creating overly permissive firewall rules
- Not updating firewall configurations
- Disabling the firewall
- Ignoring firewall logs
- Blocks unauthorized access
- Filters malicious traffic
- Protects network services
- Reduces the attack surface
- Enforces security policies
Network Address Translation (NAT) allows multiple devices on a private network to share a single public IP address while providing an additional layer of network isolation.
The repository includes screenshots demonstrating:
- Windows Defender Firewall Home
- Existing Inbound Rules
- Creating the Firewall Rule
- Block Telnet Port 23 Rule
- Firewall Configuration Restored
Successfully configured and tested a Windows Defender Firewall inbound rule to block TCP Port 23 (Telnet). After verification, the rule was removed to restore the original firewall configuration. This task provided practical experience in firewall management, network traffic filtering, and basic Windows firewall administration.