UFW (uncomplicated firewall) is a command-line tool designed to simplify firewall management on Linux systems, particularly those based on Ubuntu. Built on top of iptables, it provides a user-friendly way to define rules for controlling network traffic, such as allowing or blocking specific ports, IP addresses, or services. UFW is relevant for system administrators and developers who need to secure servers without dealing with the complexity of raw iptables commands, offering a straightforward approach to managing both IPv4 and IPv6 traffic.
This cheat sheet-style guide provides a quick reference to common UFW use cases and commands, including examples of how to allow and block services by port, network interface, and source IP address. It also covers default policies, application profiles, SSH access, and advanced usage scenarios, making it a practical resource for securely managing firewall rules on Ubuntu systems.
Key Takeaways
UFW Simplifies Firewall Management: UFW is a user-friendly interface for managing iptables, designed to simplify firewall configuration on Ubuntu-based systems.
Default Policies Are Secure by Design: By default, UFW denies all incoming connections and allows all outgoing connections, creating a secure baseline for most servers.
Always Allow SSH Before Enabling UFW: If youâre connected via SSH, enable SSH access with sudo ufw allow OpenSSH before activating UFW to avoid losing remote access.
Use Application Profiles When Available: UFW integrates with application profiles (e.g., Nginx Full, OpenSSH), allowing easier rule creation without specifying port numbers manually.
Support for IP-Based Rules: You can allow or block traffic from specific IP addresses or subnets using simple commands like ufw allow from IP or ufw deny from subnet.
Interface-Specific Rules Offer Granular Control: UFW allows rule targeting per network interface, which is useful for multi-interface systems and virtualized environments.
UFW Integrates with Both IPv4 and IPv6: Rules apply to both IP versions unless explicitly disabled. Youâll see (v6) entries in the status output for IPv6 rules.
Docker Can Conflict with UFW: Docker modifies iptables directly, potentially bypassing UFW rules unless additional configuration is applied.
UFW Rules Can Be Reset or Deleted Easily: Use ufw reset to wipe all rules or ufw delete to remove specific ones, including by rule number for precision.
Best Practices Enhance Security and Maintainability: The guide emphasizes clear practices: setting default policies early, backing up rule sets, using logging, and avoiding use of firewalld alongside UFW. <$>
How To Use This Guide
This guide is in cheat sheet format with self-contained command-line snippets.
Jump to any section that is relevant to the task you are trying to complete.
When you see highlighted text in this guideâs commands, keep in mind that this text should refer to IP addresses from your network.
Remember that you can check your current UFW ruleset with sudo ufw status or sudo ufw status verbose.
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How to Verify UFW Status
To check if ufw is enabled, run:
sudo ufw status
Output
Status: inactive
The output will indicate if your firewall is active or not.
How to Enable UFW
If you get a Status: inactive message when running ufw status, it means the firewall is not yet enabled on the system. Youâll need to run a command to enable it.
Note: By default, when enabled UFW will block external access to all ports on a server. In practice, that means if you are connected to a server via SSH and enable UFW before allowing access via the SSH port, youâll be disconnected. Make sure you follow the section in this guide on how to enable SSH access before enabling the firewall if thatâs your case.
To enable UFW on your system, run:
sudo ufw enable
Youâll see output like this:
Output
Firewall is active and enabled on system startup
UFW Default Policies
When you enable UFW for the first time, it applies a set of default policies that define how the firewall handles incoming and outgoing connections. By default, UFW is configured to:
Deny all incoming connections
Allow all outgoing connections
You can verify the current default policy settings with the following command:
sudo ufw status verbose
Output
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), deny (routed)
New profiles: skip
If you want to change the default behavior, you can update the default policies using the following commands:
To deny all incoming connections (recommended for most servers):
sudo ufw default deny incoming
To allow all outgoing connections (the default):
sudo ufw default allow outgoing
To deny all forwarded traffic (relevant for routers and gateways):
sudo ufw default deny routed
These default rules act as a baseline. Once set, you can explicitly allow trusted connections using ufw allow rules, as described in the other sections of this guide.
You can always reapply or reset your default policies as needed, depending on how restrictive or open you want your firewall to be.
How to Disable UFW
If, for some reason, you need to disable UFW, you can do so with the following command:
sudo ufw disable
Be aware that this command will fully disable the firewall service on your system.
How UFW Integrates with iptables
UFW is a user-friendly front-end for managing iptables, the underlying packet filtering framework used by most Linux systems. When you configure firewall rules using UFW, it translates those rules into iptables syntax behind the scenes.
This means that:
You donât need to write iptables rules manually.
Changes made through UFW are automatically applied via iptables.
Both IPv4 and IPv6 rules are managed unless IPv6 support is explicitly disabled in UFWâs configuration.
To check whether UFW is managing your iptables rules, you can inspect the raw iptables output:
sudo iptables -L
Youâll see chains like ufw-before-input, ufw-user-input, and others, which are automatically created and managed by UFW to enforce its policies.
UFW stores its persistent rule definitions in configuration files, typically under:
Output
/etc/ufw/
Most users never need to edit these files directly. However, if you also manage iptables rules manually or through other tools (like Docker or custom scripts), you should be aware that UFW might overwrite or conflict with those rules.
Tip: If youâre running UFW and also applying manual iptables rules, itâs best to apply custom rules through UFW or use UFWâs before.rules and after.rules configuration files to ensure compatibility.
While UFW simplifies rule management, iptables still does the actual packet filtering at the kernel level. Think of UFW as a command-line assistant that speaks iptables fluently, so you donât have to.
How to Block an IP Address
To block all network connections that originate from a specific IP address, run the following command, replacing the highlighted IP address with the IP address that you want to block:
sudo ufw deny from 203.0.113.100
Output
Rule added
In this example, from 203.0.113.100 specifies a source IP address of â203.0.113.100â.
If you run sudo ufw status now, youâll see the specified IP address listed as denied:
All connections, coming in or going out, are blocked for the specified IP address.
How to Block a Subnet
If you need to block a full subnet, you can use the subnet address with the from parameter in the ufw deny command. This would block all IP addresses in the example subnet 203.0.113.0/24:
sudo ufw deny from 203.0.113.0/24
Output
Rule added
How to Block Incoming Connections to a Network Interface
To block incoming connections from a specific IP address to a specific network interface, run the following command, replacing the highlighted IP address with the IP address you want to block:
sudo ufw deny in on eth0 from 203.0.113.100
Output
Rule added
The in parameter tells ufw to apply the rule only for incoming connections, and the on eth0 parameter specifies that the rule applies only for the eth0 interface. This might be useful if you have a system with several network interfaces (including virtual ones) and you need to block external access to some of these interfaces, but not all.
How to Allow an IP Address
To allow all network connections that originate from a specific IP address, run the following command, replacing the highlighted IP address with the IP address that you want to allow access:
sudo ufw allow from 203.0.113.101
Output
Rule added
If you run sudo ufw status now, youâll see output similar to this, showing the word ALLOW next to the IP address you just added.
You can also allow connections from a whole subnet by providing the corresponding subnet mask for a host, such as 203.0.113.0/24.
How to Allow Incoming Connections to a Network Interface
To allow incoming connections from a specific IP address to a specific network interface, run the following command, replacing the highlighted IP address with the IP address you want to allow:
sudo ufw allow in on eth0 from 203.0.113.102
Output
Rule added
The in parameter tells ufw to apply the rule only for incoming connections, and the on eth0 parameter specifies that the rule applies only for the eth0 interface.
If you run sudo ufw status now, youâll see output similar to this:
Output
Status: activeTo Action From-- ------ ----...Anywhere on eth0 ALLOW 203.0.113.102
How to Delete UFW Rule
To delete a rule that you previously set up within UFW, use ufw delete followed by the rule (allow or deny) and the target specification. The following example would delete a rule previously set to allow all connections from an IP address of 203.0.113.101:
sudo ufw delete allow from 203.0.113.101
Output
Rule deleted
Another way to specify which rule you want to delete is by providing the rule ID. This information can be obtained with the following command:
sudo ufw status numbered
Output
Status: active
To Action From
-- ------ ----
[ 1] Anywhere DENY IN 203.0.113.100
[ 2] Anywhere on eth0 ALLOW IN 203.0.113.102
From the output, you can see that there are two active rules. The first rule, with highlighted values, denies all connections coming from the IP address 203.0.113.100. The second rule allows connections on the eth0 interface coming in from the IP address 203.0.113.102.
Because UFWâs default policy denies all incoming traffic, a specific DENY rule is only necessary to override a more permissive ALLOW rule. You can remove this rule if you donât have any conflicting ALLOW rules for that source.
To delete a rule by its ID, run:
sudo ufw delete 1
You will be prompted to confirm the operation and to make sure the ID youâre providing refers to the correct rule you want to delete.
Output
Deleting:
deny from 203.0.113.100
Proceed with operation (y|n)? y
Rule deleted
If you list your rules again with sudo ufw status, youâll see that the rule was removed.
Upon installation, applications that rely on network communications will typically set up a UFW profile that you can use to allow connections from external addresses. This is often the same as running ufw allow from, with the advantage of providing a shortcut that abstracts the specific port numbers a service uses and provides a user-friendly nomenclature to referenced services.
To list which profiles are currently available, run the following:
sudo ufw app list
If you installed a service such as a web server or other network-dependent software and a profile was not made available within UFW, first make sure the service is enabled. For remote servers, youâll typically have OpenSSH readily available:
Output
Available applications:
OpenSSH
To enable a UFW application profile, run ufw allow followed by the name of the application profile you want to enable, which you can obtain with a sudo ufw app list command. In the following example, weâre enabling the OpenSSH profile, which will allow all incoming SSH connections on the default SSH port.
sudo ufw allow "OpenSSH"
Output
Rule added
Rule added (v6)
Remember to quote profile names that consist of multiple words, such as Nginx HTTPS.
To disable an application profile that you had previously set up within UFW, youâll need to remove its corresponding rule. For example, consider the following output from sudo ufw status:
sudo ufw status
Output
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Nginx Full ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Nginx Full (v6) ALLOW Anywhere (v6)
This output indicates that the Nginx Full application profile is currently enabled, allowing any and all connections to the web server both via HTTP and via HTTPS. If you want to allow only HTTPS requests from and to your web server, you must first enable the most restrictive rule, which in this case would be Nginx HTTPS, and then disable the currently active Nginx Full rule:
Remember, you can list all available application profiles with sudo ufw app list.
How to Allow SSH
When working with remote servers, youâll want to make sure that the SSH port is open to connections so that you are able to log in to your server remotely.
The following command will enable the OpenSSH UFW application profile and allow all connections to the default SSH port on the server:
sudo ufw allow OpenSSH
Output
Rule addedRule added (v6)
Although less user-friendly, an alternative syntax is to specify the exact port number of the SSH service, which is typically set to 22 by default:
sudo ufw allow 22
Output
Rule addedRule added (v6)
How to Allow Incoming SSH from a Specific IP Address or Subnet
To allow incoming connections from a specific IP address or subnet, use a from directive to define the source of the connection. This will require that you also specify the destination address with a to parameter. To lock this rule to SSH only, youâll limit the proto (protocol) to tcp and then use the port parameter and set it to 22, SSHâs default port.
The following command will allow only SSH connections coming from the IP address 203.0.113.103:
sudo ufw allow from 203.0.113.103 proto tcp to any port 22
Output
Rule added
You can also use a subnet address as from parameter to allow incoming SSH connections from an entire network:
sudo ufw allow from 203.0.113.0/24 proto tcp to any port 22
Output
Rule added
How to Allow Incoming Rsync from a Specific IP Address or Subnet
The Rsync program, which runs on port 873, can be used to transfer files from one computer to another.
To allow incoming rsync connections from a specific IP address or subnet, use the from parameter to specify the source IP address and the port parameter to set the destination port 873.
The following command will allow only Rsync connections coming from the IP address 203.0.113.103:
sudo ufw allow from 203.0.113.103 to any port 873
Output
Rule added
To allow the entire 203.0.113.0/24 subnet to connect to your server via rsync:
sudo ufw allow from 203.0.113.0/24 to any port 873
Output
Rule added
How to Allow Nginx HTTP/HTTPS
Upon installation, the Nginx web server sets up a few different UFW profiles within the server. Once you have Nginx installed and enabled as a service, run the following command to identify which profiles are available:
sudo ufw app list | grep Nginx
Output
Nginx Full Nginx HTTP Nginx HTTPS
To enable both HTTP and HTTPS traffic, choose Nginx Full. Otherwise, choose either Nginx HTTP to allow only HTTP or Nginx HTTPS to allow only HTTPS.
The following command will allow both HTTP and HTTPS traffic on the server (ports 80 and 443):
sudo ufw allow "Nginx Full"
Output
Rule addedRule added (v6)
How to Allow Apache HTTP/HTTPS
Upon installation, the Apache web server sets up a few different UFW profiles within the server. Once you have Apache installed and enabled as a service, run the following command to identify which profiles are available:
sudo ufw app list | grep Apache
Output
Apache Apache Full Apache Secure
To enable both HTTP and HTTPS traffic, choose Apache Full. Otherwise, choose either Apache for HTTP or Apache Secure for HTTPS.
The following command will allow both HTTP and HTTPS traffic on the server (ports 80 and 443):
sudo ufw allow "Apache Full"
Output
Rule addedRule added (v6)
How to Allow All Incoming HTTP (port 80)
Web servers, such as Apache and Nginx, typically listen for HTTP requests on port 80. If your default policy for incoming traffic is set to drop or deny, youâll need to create a UFW rule to allow external access on port 80. You can use either the port number or the service name (http) as a parameter to this command.
To allow all incoming HTTP (port 80) connections, run:
sudo ufw allow http
Output
Rule added
Rule added (v6)
An alternative syntax is to specify the port number of the HTTP service:
sudo ufw allow 80
Output
Rule added
Rule added (v6)
How to Allow All Incoming HTTPS (port 443)
HTTPS typically runs on port 443. If your default policy for incoming traffic is set to drop or deny, youâll need to create a UFW rule to allow external access on port 443. You can use either the port number or the service name (https) as a parameter to this command.
To allow all incoming HTTPS (port 443) connections, run:
sudo ufw allow https
Output
Rule added
Rule added (v6)
An alternative syntax is to specify the port number of the HTTPS service:
sudo ufw allow 443
Output
Rule added
Rule added (v6)
How to Allow All Incoming HTTP and HTTPS
If you want to allow both HTTP and HTTPS traffic, you can create a single rule to allow traffic on both ports simultaneously. This usage requires that you also define the protocol with the proto parameter, which in this case should be set to tcp.
To allow all incoming HTTP and HTTPS (ports 80 and 443) connections, run:
sudo ufw allow proto tcp from any to any port 80,443
Output
Rule added
Rule added (v6)
How to Allow MySQL Connection from a Specific IP Address or Subnet
MySQL listens for client connections on port 3306. If your MySQL database server is being used by a client on a remote server, youâll need to create a UFW rule to allow that access.
To allow incoming MySQL connections from a specific IP address or subnet, use the from parameter to specify the source IP address and the port parameter to set the destination port 3306.
The following command will allow the IP address 203.0.113.103 to connect to the serverâs MySQL port:
sudo ufw allow from 203.0.113.103 to any port 3306
Output
Rule added
To allow the entire 203.0.113.0/24 subnet to be able to connect to your MySQL server, run:
sudo ufw allow from 203.0.113.0/24 to any port 3306
Output
Rule added
How to Allow PostgreSQL Connection from a Specific IP Address or Subnet
PostgreSQL listens for client connections on port 5432. If your PostgreSQL database server is being used by a client on a remote server, you must explicitly allow this traffic.
To allow incoming PostgreSQL connections from a specific IP address or subnet, specify the source with the from parameter, and set the port to 5432:
sudo ufw allow from 203.0.113.103 to any port 5432
Output
Rule added
To allow the entire 203.0.113.0/24 subnet to be able to connect to your PostgreSQL server, run:
sudo ufw allow from 203.0.113.0/24 to any port 5432
Output
Rule added
How to Block Outgoing SMTP Mail
Mail servers, such as Sendmail and Postfix, typically use port 25 for SMTP traffic. If your server shouldnât be sending outgoing mail, you may want to block that kind of traffic. To block outgoing SMTP connections, run:
sudo ufw deny out 25
Output
Rule added
Rule added (v6)
This configures your firewall to drop all outgoing traffic on port 25. If you need to reject outgoing connections on a different port number, you can repeat this command and replace 25 with the port number you want to block.
How to Reset UFW to Default Configuration
Over time, your UFW rule set may grow cluttered with test rules, duplicate entries, or outdated configurations. If you need a clean slate, UFW provides a built-in command to reset its configuration back to the default state.
Resetting UFW will:
Disable the firewall (UFW will no longer be active)
Remove all numbered rule references used for deletion
To perform a full reset of UFW, run the following command:
sudo ufw reset
Output
Resetting all rules to installed defaults. This may disrupt existing ssh connections. Proceed with operation (y|n)?
Type y to confirm.
This action is useful when:
Your firewall is behaving unexpectedly
Youâve misconfigured multiple rules and want to start fresh
Youâre switching server roles (e.g., from a web server to a database node)
You want to standardize your configuration across systems
Note: If youâre connected to the server remotely via SSH, do not reset UFW unless youâre prepared to immediately re-allow SSH access. Otherwise, you risk locking yourself out once the firewall is re-enabled.
Once youâve reset UFW, youâll need to reconfigure essential access rules. For example, to re-allow SSH and activate the firewall again:
sudo ufw allow OpenSSHsudo ufw enable
You can then rebuild your rule set from scratch based on your current needs.
How to Clarify the Difference Between UFW and firewalld
While UFW is the default firewall manager on Ubuntu-based systems, other Linux distributions, especially Red Hat-based ones, use a different tool: firewalld. Both tools serve the same purpose of managing firewall rules, but they take different approaches and are designed with different priorities in mind.
What is firewalld?
firewalld is a firewall management tool that provides a dynamic interface for managing rules. It utilizes the concept of zones, which lets you define different trust levels for network interfaces (for example: public, internal, dmz). This makes it ideal for more complex environments where different parts of the system or network require different firewall behavior.
firewalld supports both runtime and permanent rules. Runtime changes take effect immediately without restarting the service, making it suitable for on-the-fly updates. Permanent rules persist across reboots and are typically used for long-term configuration.
It also includes rich rule support (such as service-based access, ICMP types, interface filtering, and source/destination address control) and is often managed through graphical tools like firewall-config or Cockpit.
UFW versus firewalld
Feature
UFW
firewalld
Default on
Ubuntu, Debian
RHEL, CentOS, Fedora
Configuration style
Static, rule-based
Dynamic, zone-based
Zones
Not supported
Fully supported
Rule types
Persistent
Runtime and permanent
GUI support
GUFW (Graphical Uncomplicated Firewall) (basic)
firewall-config, Cockpit (advanced)
Syntax simplicity
Simple, human-readable CLI
More flexible but more complex
Backend
iptables or nftables (indirectly)
iptables or nftables
Use case focus
Basic host firewalling
Multi-interface, multi-zone environments
How to Choose Between UFW and firewalld
Choose UFW if youâre running a single-purpose server, need quick rule setup, or prefer a minimal interface.
Choose firewalld if youâre dealing with multi-interface setups, virtual networks, or enterprise-grade configurations where zone-based configurations and live rule updates are important.
Note: Avoid using UFW and firewalld on the same system. They manage the same underlying iptables or nftables rules and can conflict with each other, causing unexpected behavior.
How to Check and Manage firewalld Status
To check if firewalld is running on your system:
sudo systemctl status firewalld
To stop and disable it if you are using UFW, use the following commands:
To get the most out of UFW while minimizing misconfigurations and downtime, consider following these recommended best practices when setting up and maintaining your firewall.
Always Allow SSH Before Enabling the Firewall
If youâre connected to a server over SSH, make sure to allow SSH before enabling UFW to avoid being locked out:
sudo ufw allow OpenSSHsudo ufw enable
Failing to do this will block your remote access the moment UFW is enabled.
How to Set Default Policies Before Adding Rules
Set your default incoming and outgoing policies early in your configuration so youâre starting with a secure baseline:
Only then should you begin explicitly allowing the services you need.
Instead of manually allowing ports, use predefined application profiles:
sudo ufw allow "Nginx Full"
To see what profiles are available:
sudo ufw app list
This makes rule management easier and reduces the chance of human error when typing port numbers or protocols.
How to Be Specific With IPs, Ports, and Protocols
Limit exposure by tightening rules as much as possible. For example, instead of opening SSH to the world:
sudo ufw allow from 203.0.113.0/24 to any port 22 proto tcp
This approach minimizes your serverâs attack surface by only allowing trusted sources.
How to Use Numbered Rules for Easier Management
When you need to remove or audit specific rules, use:
sudo ufw status numbered
This makes it easier to delete rules precisely without needing to retype full command strings:
sudo ufw delete 2
How to Test Changes in a Maintenance Window (if possible)
Firewall misconfigurations can disrupt services. If youâre modifying rules on a production server, test during off-peak hours or schedule a short maintenance window to reduce risk.
Use Logging to Monitor Activity
Enable logging to capture dropped connections and debug firewall behavior:
sudo ufw logging on
Logs are typically stored in:
/var/log/ufw.log
You can control verbosity with:
sudo ufw logging low # or medium / high / full
How to Back Up Rules Before Making Major Changes
Before resetting or reworking your UFW configuration, save the current ruleset:
sudo ufw status numbered > ufw-backup.txt
This lets you recreate or review past configurations if something goes wrong.
Donât Use UFW and firewalld Together
Stick to one firewall management system. Running both UFW and firewalld simultaneously can cause rule conflicts and unpredictable behavior.
Disable the one youâre not using:
sudo systemctl disable firewalld
Or:
sudo ufw disable
Following these best practices will help ensure your firewall is secure, maintainable, and doesnât interrupt your serverâs connectivity.
Frequently Asked Questions (FAQs)
1. What is the default UFW policy?
By default, UFW is configured to deny all incoming connections and allow all outgoing connections. This means no external device can initiate a connection to your system unless explicitly allowed, while your system is free to access external resources.
You can view the current default policies by running:
To allow all traffic from a specific IP address, use the allow from syntax. Replace the IP with the address you want to permit:
sudo ufw allow from 203.0.113.101
This creates a rule that permits all types of connections from that IP to your server. If you want to restrict it to a specific port or protocol, you can add more parameters:
sudo ufw allow from 203.0.113.101 to any port 22 proto tcp
This allows only SSH (TCP port 22) traffic from the given IP.
3. How can I check which rules are currently active?
To view your active UFW rules, run:
sudo ufw status
For more detailed output, including default policies and logging status, use the verbose flag:
sudo ufw status verbose
If you want to view rules with line numbers (helpful for deleting specific rules), run:
sudo ufw status numbered
4. Can UFW block outgoing traffic?
Yes, UFW can be used to block outgoing connections. While UFW allows all outbound traffic by default, you can add rules to deny specific ports or destinations.
To block all outgoing SMTP traffic on port 25, for example:
sudo ufw deny out 25
You can also block outgoing traffic to specific IP addresses or ranges:
sudo ufw deny out to 203.0.113.0/24
To change the default policy for all outbound traffic:
sudo ufw default deny outgoing
Be cautious with outbound rules, especially on servers that require external access for updates, backups, or package installations.
5. Does UFW work with IPv6?
Yes, UFW supports both IPv4 and IPv6 by default. When you enable a rule like sudo ufw allow ssh, it creates rules for both IPv4 and IPv6 unless configured otherwise.
You can verify IPv6 rules are active by checking the output of:
sudo ufw status
Youâll see entries like:
Output
OpenSSH (v6) ALLOW Anywhere (v6)
To disable IPv6 support in UFW, edit the configuration file:
sudo nano /etc/default/ufw
Set:
Output
IPV6=no
Then reload UFW:
sudo ufw disable && sudo ufw enable
6. Can I use UFW with Docker?
UFW and Docker can conflict because Docker bypasses the default iptables rules UFW sets up. As a result, Docker containers may be exposed to the network even if UFW appears to block traffic.
If youâre running Docker and need strict firewall control, youâll need to:
Use Dockerâs own firewall rules
Or reconfigure iptables policies to work correctly with UFW
To secure your system while running Docker, consider using Dockerâs --iptables=false option and managing container traffic manually, or use advanced UFW/Docker integration scripts.
Note: By default, Docker modifies iptables directly. This can override or bypass UFW rules unless explicitly accounted for.
7. How do I delete a specific UFW rule?
There are two main ways to delete a UFW rule:
By repeating the exact rule:
sudo ufw delete allow from 203.0.113.101
By rule number:
First, list rules with numbers:
sudo ufw status numbered
Then delete a rule by its number:
sudo ufw delete 2
Youâll be prompted to confirm the deletion before the rule is removed.
Many networked applications (like Nginx, Apache, or OpenSSH) register UFW profiles when installed. You can view all available profiles with:
sudo ufw app list
To see what ports a profile covers, run:
sudo ufw app info "Nginx Full"
This will show which ports the profile opens and any associated protocols. Using application profiles simplifies rule management and abstracts away the need to remember specific port numbers.
Conclusion
UFW is a powerful yet approachable tool for managing firewall rules on Ubuntu systems. With its simple syntax and built-in support for both IPv4 and IPv6, UFW makes it easy to enforce access controls without needing to write complex iptables rules by hand.
This guide has covered the most common UFW commands and use cases, including how to allow or deny traffic by port, IP address, and network interface, as well as how to manage application profiles and reset the firewall configuration. Most of these examples can be adapted to fit your own network needs by modifying parameters like IP addresses or port numbers.
For more in-depth details on UFW command options and advanced usage, consult the manual using man ufw or explore Ubuntuâs official documentation.
To explore and learn more about firewall configuration and Linux networking, check out these helpful resources:
