Author Archives: WFilter

Software solutions to monitor internet usage in business networks.

To save internet bandwidth and raise productivity, administrators need to know bandwidth usage and internet activities in business networks. There are network firewall appliances with this ability, while in this post, I will introduce several software monitoring solutions.

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1. Passby monitoring on a mirroring port.

“Port mirror” is a feature of manageable switches or routers. With “port mirroring”, you can get a copy of packets from other ports. So you can setup a software program in the target port pc to monitor all network traffic. This is called as “passby monitoring”. The network diagram:

With WFilter internet content filter installed, you will be able to monitor bandwidth, internet activities and deploy internet access policies. Screenshots:

2. SNMP-based monitoring

Comparing to “port mirroring”, SNMP-based monitoring is easier to setup with less features. However, it’s also very convenient to monitor bandwidth with SNMP. Below are screenshots from PRTG.

Image result for PRTG

3. Linux network bridge

Network bridge is more powerful, with the ability to monitor traffic, allocate bandwidth, filter internet activities… A network bridge shall be deployed between your router/firewall and switch.

To setup a network bridge, you need a pc with two network cards(wired adapters only). I would recommend you to use WFilter NG firewall as the operation system. It’s a dedicated linux distribution for internet content filtering and firewall. Below are screenshots from WFilter NGF:

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Wireless authentication solutions for business network.

Most business networks are now providing WiFi access for employees and customers. Since everyone can access WiFi network, unauthorized access will bring virus attack and intruders. So you need to pay more attention to your network security.

Usually, you have below options:

Set WiFi users in a separator VLAN, which shall only have limited access to enterprise resources. This is the first door to keep intruders out.
Enable user authentication for WiFi users.
Enable ip-mac binding for WiFi users.
Record internet usage history for WiFi users, including IP, MAC, visited websites.

In this post, I will introduce the “Web Auth” feature of WFilter NG firewall. For WiFi clients, the most widely used authentication is “Web Authentication”(Portal Authentication). Clients won’t have internet access until authenticated in a web portal. For IOS and windows, the web portal will show up automatically.

1. User & Pass Authentication

When enabled, WiFi clients will be required for username and password.

Various authentication method are supported, including “Local Auth”, “Email Auth”, “Ldap Auth” and “Radius Auth”.

If you have an existing ldap domain, you can authenticate with domain users.
Users also can authenticate with email accounts.
You also can define local users in WFilter for authentication.
Remote radius server is also supported.

You can set internet access policy, query history and reports based on usernames.

2. Third Party Auth

“Third party authentication” is designed for marketing purpose. You have “wechat WiFi” and “facebook WiFi” in default. When enabled, users shall checkin in your facebook page to access internet.

Download WFilter NG firewall now!

API overview of WFilter NGF.

WFilter NGF has a built-in API library for developers to manipulate the entire system or integrate WFilter features. With APIs, you’re able to:

1. Get bandwidth history.
2. Get online users, including ip, mac, account, live connections.
3. Terminate user connections, kick off user…
4. Add/remove user from virtual group to apply policies.
5. Extend user expire date.

In this post, I will use an API example to demonstate the API library usage of WFilter NGF. The requirement is simple: “a API call to set access policy and bandwidth rate limit for an ip address”.

1. First, we need to setup WFilter NGF.

Because “access policy” and “bandwidth shaper” are separate modules in WFilter NGF, we need to setup a virtual group with policies applied. In the API call, we only need to add IP addresses into the virtual group to apply the rules.

1.1) New a “limited access” virtual group.

1.2) Setup policies to this group.

2. Use php to call WFilter API.

Now, we’ve setup policies for the virtual group. To implement policies to an IP address, we only need to add this IP into this group. We have a php SDK, you need to include the WFilterNGF.php to call the API functions.

Isn’t it simple? You may check more details in WFilter API. If you have any suggestions or requirement, please feel free to contact us.

Three ways to block torrent traffic in your network.

Torrent downloading is annoying and can consume most of your bandwidth, so you might want to block torrent in your network. There are several ways to block torrent in your network. While in this post, I will introduce three solutions to block torrent(bittorrent, utorrent, qtorrent) with WFilter internet content filter and WFilter NG firewall.

Please be aware that “WFilter internet content filter(ICF)” and “WFilter NG firewall(NGF)” are total different products. WFilter ICF is a windows program, which is designed for pass-by deployment on a mirroring port. While WFilter NGF is a dedicated linux firewall system.

1. Block torrent with WFilter ICF

As you can see in the diagram, the WFilter internet content filter(ICF) shall be connected to a mirroring port in your router or switch. So it can analysis network packets and deploy internet access policies. Steps to block torrent with WFilter ICF:

2. Block torrent with WFilter NGF as a network bridge.

Network topology diagram:

WFilter NGF acts as a network bridge, sitting between your router and switch. So it can filter internet traffic.

3. Block torrent with WFilter NGF as a network gateway.

Network topology diagram:

In this topology, WFilter NGF acts as the gateway of your network to deploy internet access policies. Please be aware that you can install WFilter NGF in a virtual machine to act as a virtual gateway, here is a guide: Using a pre-built VMWare image of WFilter NG Firewall

You can setup “application control” policies to block torrent with below steps:

When deployed and configured properly, both WFilter ICF and WFilter NGF can block torrent completely. All torrent clients will have zero uploading and downloading speed.

WFilter ICF homepage: WFilter Internet Content Filter

WFilter NG homepage: WFilter NG firewall

WFilter videos: WFilter Videos

How to setup ip-mac binding in your switch?

For security purpose, you might want to bind ip address with MAC address for client devices. There are several IP-mac binding solutions, including ARP binding, port-based binding…

In this post, I will introduce the steps to setup port-based IP-MAC binding in your switch.

1. Cisco 2950

Syntax of cisco 2950 port-based IP-MAC binding.
Switch#config terminal
Switch(config)#Interface fastethernet 0/1
Switch(config-if)#switchport port-security mac-address xxxx.xxxx.xxxx ip-address 192.168.x.x

2. Huawei S5700

Syntax of Huawei S5700 port-based IP-MAC binding.
#interface GigabitEthernet 1/0/1
#user-bind mac-addr xxxx-xxxx-xxxx ip-addr 10.100.11.2

Other models have similar syntax. Port-based binding in switch is powerful, but it’s rather complicated to setup and maintaince, especially when you have a lot clients.

However, IP-MAC binding in gateway is easier to setup, also with powerful features, please check below screenshots in WFilter NG firewall.

3. WFilter NGF

When configured, DHCP clients will be assigned with static ip addresses; clients not matching the ip-mac binding relationship will be blocked.

A site to site ipsec vpn example.

With the “IPSec VPN” module in WFilter NGF, you can build a secure site-to-site VPN by a few clicks. In this post, I will demonstrate a typical usage of site to site ipsec vpn. Please check the diagram at first.

When successfully configure, A,B,C will have full access of each other. Please check below steps:

Suppose you have 3 networks:

Headquarter A, static public ip address, LAN subnet is 192.168.10.0/24.
Branch B, PPPoE internet access, LAN subnet is 192.168.30.0/24.
Branch C, PPPoE internet access, LAN subnet is 172.16.1.0/24.

Now let me guide you to build a virtual private network(VPN) for these three locations.

1 Settings for Headquarter A

Setup the IPSec tunnel

Enable forwarding of branches

Without this setting, branches can access headquarter, but no access between branches.

2 Branch B

Setup the IPSec tunnel

3 Branch C

Setup the IPSec tunnel

By above steps, AB and AC are now connected. If you also want B and C to communicate with each other, you need to add B&C subnets in headquartor’s local subnet.

Turn your old PC into a firewall appliance.

You may have an old desktop PC sitting in a closet or somewhere. Did you know that you still can make it useful? In this guide, I will demonstrate the steps to turn your old pc into a network firewall appliance.

1. First, please check what you need to prepare.

1.1) an old desktop pc.
1.2) a gigabit ethernet adapter.
1.3) a usb stick.

2. Mount the ethernet adapter and connect the cables.

There is only one onboard ethernet adapter, so I need to add another PCI adapter.

The green chip on left is the new added ethernet adapter.

Now let’s connect the cables.

3. Install WFilter NGF system.

Now you can install WFilter NGF with your usb stick. Please check a more detailed guide at here: WFilter NG Firewall Installation Guide

You shall be able to the console upon successful installation.

Set your laptop to “dynamic ip address” and open http://192.168.10.1 in browser, you can access webUI to set the system up.

4. See what I get.

The CPU is “Intel Pentium Dual CPU E2160 1.8G”, 2GB DDR2 RAM, 160G harddisk.

Let’s check the performance. Wow, it can handle 200+ clients with 20K concurrent connections. Isn’t it amazing?

For more features of WFilter NGF, please check: WFilter NG firewall

DIY a firewall appliance for your network.

As WFilter NG firewall released a free 50-user license, there is an opportunity for small business and home users to DIY powerful firewall appliances. ou may read this post first to take a sight of the free license: Free license of WFilter NG firewall is now available

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In this post, I will guide you certain steps to build a firewall appliance.

1. First, you need to buy an appliance box and a harddisk.

1). A 4/6 interfaces atom D525 networking appliance. (Less than $200)

2). A Seagate 1TB disk.

3). One usb stick.

2. Mount the disk.

3. Get a display monitor, and burn WFilter ISO into the usb stick.

Here is a guide for installation: http://wiki.wfilterngf.com/Installation_of_WFilter_ROS

Console terminal after installation:

4. Now connect your laptop to LAN interface and setup basic networking parameters.

Set laptop to “obtain ip address automatically”, then open http://192.168.10.1 in your browser.

Choose the free license:

5. Connect all the cables.

6. Done, now you can setup more policies to speed up your internet access.

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Isn’t it exciting? You won’t be able to find any better solution for small networks.

Download WFilter NG firewall now!

Free license of WFilter NG firewall is now available.

Free license of WFilter NG firewall is now available in the last build of WFilter NGF(1.1.2017.06.05). Except remote support, free license has all features of WFilter for 50 users. You can use this license in any networks, including business.

Now let’s see what we can do with this free license.

1. Choose “free license” on first time login.

2. Powerful reports and statistics.

3. Archive web browsing and email history.

Web activity recording

Email activity recording

SSL inspector

4. Deploy internet content filtering policies

With the free license, you also can get “website black&white list”, “website category filtering”, “application control”, “IP-mac binding”, “Web content pushing”…

5. Bandwidth optimization and rate limit

Free solutions for bandwidth priority optimization, bandwidth rate limiter and multiple WAN load-balancing and WAN fail-over.

6. Various user authentication.

Local accounts, active directory integration, PPPoE, web authentication(facebook WiFi).

And the “ISP management” module, a total solution for users/bandwidth management.

7. VPN tunnels

8. Extensions

9. License

Now let’s check the license: life-time free for 50 users.

Isn’t it exciting? You won’t be able to find any better solution for small networks.

Download WFilter NG firewall now!

Tips to stop WannaCry ransomware in your network.

In this weekend, WannaCry swept Europe and Asia quickly, locking up critical systems like the UK’s National Health Service, a large telecom in Spain, several universities in China and other businesses and institutions around the world. Once infected, the infected computer denies access, and demands the equivalent of around $300 in bitcoin for decryption.

In this post, I would introduce the important tips to block WannaCry attack.

1. Install Security Patches. Microsoft has released security patches that fix SMB flaw currently being exploited by the WannaCry ransomware, with most version of Windows supported — including Windows XP, Vista, Windows 8, Server 2003 and 2008.
2. Block incoming connections on TCP port 445 in your router/firewall. This rule blocks attacks from internet.
3. For windows DMZ hosts, you also need to block TCP port 445 in firewall settings.
4. To protect VLANs being attacked by an infected VLAN, you can block TCP port 445 in VLAN ACL rules of your core switch.

Using the “network health checker” extension of WFilter, you also can check whether there are “Suspicious Hosts ” in your LAN network. Hosts with massive connections will be identified as “Suspicious”.