Category Archives: Network management

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.

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Usually, you have below options:

  1. 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.
  2. Enable user authentication for WiFi users.
  3. Enable ip-mac binding for WiFi users.
  4. 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.

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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.


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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

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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.

ipsecVPN

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

Ipsec center01.png

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  • Enable forwarding of branches

Without this setting, branches can access headquarter, but no access between branches. Ipsec center03.png

2 Branch B

  • Setup the IPSec tunnel

Ipsec client01.png

  • Add a routing rule to branch C

Set branch C’s LAN subnet to “Destination”, set headquarter A’s public IP to “Gateway”. Without this routing rule, branch B can not access branch C.

Ipsec client02.png

3 Branch C

  • Setup the IPSec tunnel

Ipsec client03.png

  • Add a routing rule to branch B

Set branch B’s LAN subnet to “Destination”, set headquarter A’s public IP to “Gateway”. Without this routing rule, branch C can not access branch B.

Ipsec client04.png

By above steps, A,B,C are now in a virtual private network. If you don’t want access between B and C, there is no need to add the firewall and routing rules.

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.

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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.

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

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

usb

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Console terminal after installation:install02_en

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.install03_en

Choose the free license:install04_en

5. Connect all the cables.

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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.

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

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

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2. Powerful reports and statistics.

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3. Archive web browsing and email history.

Web activity recording

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Email activity recording

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SSL inspector

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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”…

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5. Bandwidth optimization and rate limit

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

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6. Various user authentication.

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

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

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7. VPN tunnels

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8. Extensions

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9. License

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

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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!

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.

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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.

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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”.

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Powerful networking diagnose tool sets for IT professionals.

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As a network professional, when things go wrong in your network, the right tools are required to minimize network downtime.
In this post, I will reveal you the extension system in WFilter, a powerful tool sets for networking issues.

At a first galance

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All WFilter systems have an “extension” library, which contains a powerful free tool sets for IT administrators. Most extensions are free. Even supported in WFilter free, a freeware for network internet filtering and monitoring.

Now let’s see what we can do with WFilter extensions:

1. Scan client devices in network

With “network scan” extension, you can get a complete list of network clients, including IP, MAC, manufactor and open ports…
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2. Discover and scan DHCP services in network

The “Network DHCP discover plugin” of WFilter can scan DHCP services in your network by a single click. It will list all dhcp servers ip addresses, MAC addresses and MAC manufactures.

3. Detect NAT sharing services in network

Detect illegal NAT sharing in network.

4. Check network health of availability, IP conflict, ARP spoof and broadcast storm

This extension can:

  1. check availability and ping performance of dns servers.
  2. check availability and ping performance of internet sites.
  3. check availability and ping performance of local network hosts.
  4. check whether there is ip conflict in local network.
  5. check whether there is arp spoof running in local network.
  6. check whether there is broadcast storm in local network.

5. Scan proxy servers in network

6. Graph ping performance of multiple hosts

With this plugin, you can get ping performance and graph reports for multiple hosts in a period of time.

A complete extesions list can be found at here: WFilter extensions. And more will come. The most important thing is that most extension are free, supported in “WFilter internet content filter(commercial)”, “WFilter NG firewall” and “WFilter Free”.

Isn’t it exicting? Download WFilter Now!

How to bind ip address with mac address in network?

IP and MAC address binding is usually configured in network switch or router(gateway). An effective IP-MAC binding solution needs to:
1. Be able to integrate with the DHCP server to assign static IPs to clients.
2. Have option to block or allow internet for un-bound devices.
3. Be able to do IP-MAC binding in multi-subnet networks.

In this post, I will demonstrate the “IP-MAC binding” feature in WFilter NG firewall. For IP-MAC binding in “WFilter internet content filter”, please check: “WFilter IP-MAC binding solution“.

1. IP-MAC Binding List

You can define the IP-MAC binding list in “Modules”->”Access Policy”->”IP-MAC Binding”. When listed, these devices will always be assigned with static IP addresses when using dynamic IP address.

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2. Settings

Below options are available in the “IP-MAC binding” module:
1. For unlisted IP addresses, you can choose “Allow all”, “Block all” or “Block below IP ranges”.
2. For unlisted MAC addresses(devices), you can configure whether to assign IP address or not.

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3. Multi-subnet IP-MAC binding solution

Your network is multi-subnet? No worry. With “MAC address detector”, WFilter NGF is able to retrieve MAC addresses from your core switch. So you can bind IP address with MAC address, even in a multi-subnet network.

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A guide of “IP-MAC binding” in WFilter NGF can be found at: IP-MAC binding.

How to detect ip conflicted devices in your network with WFilter?

IP conflict in local network can be annoying. When ip conflicts happens, it will cause connection issues. And it’s rather difficult for an IT administrator to locate the conflicted devices.

With WFilter, life is easier.

First, you can block the conflicted devices with a message. As shown in below figure, you can send a message “Your ip address conflicts with our server, please correct it ASAP”. This message will show up when browsing http sites. So the client can fix this issue by himself.

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Second, you can run the “Network Health Checker” extension, which can test ip conflicts in your network. The screenshots:

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Conflicted devices will be detected, with its mac address and manufacturer.

In this example, now you may talk to the person with “HuaWei” mobile to correct the conflict issue.

Extension home page: “Network Health Checker”

Wiki page: Check network health of availability, IP conflict, ARP spoof and broadcast storm

What’s the difference between Pass-by filtering and Pass-through filtering?

Filtering technologies are divided into two types: Pass-through (sever plug-in based) and Pass-by (standalone-based).

 

A Pass-by filter usually monitors and filters network traffic with the help of port mirroring while a Pass-through filter monitors and filters network traffic on a gateway or bridge.

 

The differences between Pass-by filtering and Pass-through filtering: Advantages of Pass-by filtering:

 

1. Pass-by filtering is easier to be deployed. You only need to setup a mirroring port in your switch without the need to change your network topology. However, since pass-through filtering needs to be installed in the gateway or bridge, usually you need to change your network topology to deploy a pass-through filtering product.

 

2. Pass-by filtering product, such as WFilter Enterprise, only deals with copies of network packets, without any delay of the original packets. Even a pass-by filtering product stops working, your internet connection stays alive.

 

However, because a Pass-through product “stops and checks” network packets, it is unavoidable to make slight delay to your internet access. And, when a pass-through filtering product stops working, you will lose your internet connection.

 

Disadvantages of Pass-by filtering:

 

1. Port mirroring is required for pass-by filtering, you can not monitor or filter your network without a manageable switch.

 

2. A pass-by filtering product sends RST packets to terminate TCP connections, however, UDP traffic can not be blocked by pass-by filtering. Usually, you also need to block certain UDP ports in your router for completely blocking.

 

3. Traffic shaping and QoS is unavailable in pass-by filtering, since it only deals with copies of network packets.

For more information about WFilter technical details, please check: WFilter Inside Technologies.