Showing posts with label Network. Show all posts
Showing posts with label Network. Show all posts

Reuse an old router to bridge devices to your wireless network

Reuse an old router to bridge devices to your wireless network(Credit: Ed Rhee/CNET )
Many smart or connected devices come with wired-only connections (Ethernet), like your TV,game console, DVD player, TiVo, or other streaming-media device. Unless your Internet modem or wireless router happens to be at the same location as those devices, connecting them to your wireless network can be a challenge.
Possible solutions include, power-line adapters, dedicated wireless adapters for each device, or installing Ethernet jacks. Unfortunately, those options can get expensive and each has its unique drawbacks. Another option is using a wireless bridge. A wireless bridge connects two wired networks together over Wi-Fi. The wireless bridge acts as a client, logging in to the primary router and getting an Internet connection, which it passes on to the devices connected to its LAN Jacks. You can buy a dedicated wireless bridge, but if you have an old router lying around, you might be able to convert it into a wireless bridge using DD-WRT.

Client Bridge mode
A wireless bridge connects two wired networks together over Wi-Fi.

DD-WRT is free Linux-based firmware for routers that replaces the router's factory firmware. It can breathe new life into an old router, giving it enhanced performance and new features. One of the features of DD-WRT is the ability to switch the router's function to a wireless bridge.
This tutorial, based on the DD-WRT Wiki, will go over how to configure DD-WRT for use as a wireless bridge (client bridge mode), using a Linksys WRT54G router as an example. The process is fairly straightforward but will require some time and patience to complete. In the steps below, primary router refers to the main router that you'll connect to, while bridge routerrefers to the router you're configuring as a client bridge.
Step 1: Check the DD-WRT router database to see if your router is supported. If your router isn't supported, keep an eye out at The Cheapskate blog for router deals. Rick Broida recently found a refurbished router with DD-WRT support for just $9.99.
Step 2: If your router is supported, you'll see it listed in the database and it'll include links to the firmware. It may also include device-specific directions on how to install DD-WRT, but you'll want to read over the general installation notes as well. In some cases, you'll need to install a firmware prep, prior to installing the actual DD-WRT firmware. It's possible to brick your router during installation if not performed correctly, so read the directions carefully and follow each step as noted.
Step 3: Once you've successfully installed DD-WRT, perform a hard reset on the router. This usually involves holding a reset button/pin for 30 seconds or until you see the router's lights flashing. Refer to your router's user manual to figure out the exact method for a hard reset.
Step 4: Connect an Ethernet cable from your computer to one of the LAN jacks on the bridge router, then set a static IP address on your computer. Use something like, so you'll be on the same subnet as the bridge router, which will have an IP address of
Step 5: Open a Web browser and enter in the address bar. The DD-WRT Web interface will appear and you'll be prompted to change your username and password. Choose a username and password, then click the Change Password button.
Step 6: Go to Wireless > Wireless Security, then set the same Security ModeAlgorithm, andShared Key as your primary router. Click Save.

Step 7: Go to Wireless > Basic Settings, then change the Wireless Mode to Client Bridge. Set the same Network Mode and SSID as your primary router. If your bridge router is an N router, you may also need to set the same wireless channel width as your primary router. Click Save, then Apply Settings.
Step 8: Go to Setup > Basic Setup, then fill in the router IP info. For the local IP address of the router, choose an address in the same subnet as your primary router. If your primary router is on the 192.168.1.x subnet, choose something like Leave the Subnet Mask as and enter the IP address of your primary router as the Gateway. Leave Local DNS blank and select your time zone. Optionally, you can check the box to Assign WAN Port to Switch. This converts the WAN port to a LAN port, providing you with an extra port on your bridge router. Click Apply Settings.

Step 9: Log back in to your bridge router using the new address you set (
Step 10: Go to Security > Firewall, then under Block WAN Requests, make sure that only "Filter Multicast" is checked. Click Save.

Step 11: Under Firewall Protection, make sure "SPI Firewall" is disabled, then click Apply Settings.
Step 12: Go to Setup > Advanced Routing, then set the Operating Mode to "Router." Click Save.

Step 13: Remove the static IP address from your computer and re-enable automatic IP addressing. At this point, the bridge router should pass along an IP address from the primary router to your computer, giving you access to the Internet.
Step 14: Once you've verified that your computer can access the Internet while physically connected to the bridge router, you can disconnect your computer. You're now ready to connect your wired devices to the bridge router from anywhere in your home (within range of your primary router).
  • If you're using MAC filtering on your primary router, you'll want to add the bridge router's wireless MAC address, not the LAN MAC address that's usually printed physically on the router. To find the wireless MAC address, go to Status > Sys-Info.
  • If your primary router is a Wireless-N router, but your bridge router is a Wireless-G router, you may need to set the wireless mode to a setting that supports b/g networks.
That's it. Now you can connect all your wired devices to your wireless network, even if they're not next to your primary router. It's worth mentioning that a wireless bridge is also useful when the scenario is reversed. If you have your Internet modem and primary router next to your TV, but need connectivity to your computer in another location, you can use the wireless bridge to provide a connection to your computer, printer, NAS, etc.

Courtsy :

Network Magic - A great tool for Networks

Network Magic - A great tool for Networks
Network Magic

If you're looking for a simple, free, all-in-one network management tool for a small peer-to-peer network, this is the one to get. It handles all the basic network chores, including adding new devices to the network, fixing broken network connections, setting up wireless encryption and protection, sharing printers and folders, reporting on the state of the security of each PC, and much more.
For example, the network map, pictured nearby, displays every device connected to your network, shows whether it's online or offline, and displays details about each, including the computer name, IP address, MAC address, operating system being used, shared folders, and system information such as its processor and RAM. It also lets you change the machine name, and it displays alerts about each device, such as if it isn't protected properly. Overall, it's far superior to Windows Vista's Network Map. 
The software's Status Center is also useful. It displays overall information about your network, such as whether there are any problems with overall security or with an individual PC. It also lets you troubleshoot connections, shows whether there are any intruders on the network, and displays information about wireless protection. 
Parents will appreciate some of Network Magic's features. For example, the software can monitor the use of any individual PC on the network for the Web sites it visits, the times the computer is online and which programs are being used, and then mail a daily report about it to an e-mail address. So it's ideal for parents who want to keep track of their kids' computer use. There's much more as well, including a bandwidth tester to show you your current Internet broadband speed.
Note that there are both paid and free versions of the software. The free version includes most basic features, such as repairing broken connections, issuing security alerts, monitoring network activity and the Network Map. The paid version, which costs from $24 to $40 (depending on how many PCs are on your network), delivers daily reports of Internet activity, supports remote access to your network's files and includes other advanced features.
When you install this program, you may need to tell your firewall to let this application access your network and the Internet.

Learn the Netstat Command To Understand Your Internet Connections Better

Who is connecting to my computer ? Why is my PC suddenly transferring so much data ? Where is it sending the data to ? Are there some zombie process or spyware running in the background that's actively making connections to the internet without my knowledge ? Why did my internet connection get so slow ?

If you are connected to the internet and any of the above questions trouble your mind, all you need to do is learn Netstat [network statistics], a hidden DOS Command that helps you keep an eye on your internet and network connections (both incoming and outgoing)

You can run the netstat command from directly from DOS command prompt window. We will not go into any technical details but directly jump to practical examples of using the Netstat command in real world situations:

How do I know who is connecting to my computer from the internet ?

netstat -p TCP

To display a list of external machines (IP address or Machine names with Port Number) that your computer is connnected to. If you wish to display the foreign address only in numeric form, append the -n switch.

I think a virus or trojan on my computer is sending data to the internet ? Can I confirm this

netstat -e 10

This command displays the number of bytes sent and received in real time. The command loops after every 10 seconds to give you an idea of how much data is being transferred and at what rate. If you are not transferring a file over the internet but still large data is being sent across, that signals a problem.

Which program(s) on my computer are making active connections to the internet ?

netstat -p TCP -b

This command displays the list of software executable (like Firefox.exe) that are connecting to the internet. It will also show which websites (or IP address) they are connecting to and what is the status of the connection.

ESTABLISHED - Both hosts are connected.
CLOSING - The remote host has agreed to close its connection.
LISTENING - Your computer is waiting to handle an incoming connection.

I am downloading an illegal file over a torrent network. Will others come to know about my activity ? 

Absolutely, they can run the netstat command on their own machines and your computer's IP address would appear in the command's output. Any IP address can be easily traced to a physical geographic location of the computer with a little help from the ISP.

I have subscribed to a fast broadband internet connection but the data transfer rate sometimes drops down to 0 kbps. Why ?

Run the netstat command with the -b switch and look for values under the column "state" - If you see a lot of active connections with TIMED_WAIT status, that may be holding down the speed of your internet transfer. Kill the culprit process(es) from the Task manager or if it's an essential process, restart the computer.

To learn more about the netstat command, type netstat /? at the command prompt to see a detailed help page.

Some Cisco Router Configuration and Troubleshooting Commands

clear logging

To clear messages from the logging buffer, use the clear logging privileged EXEC command.
clear logging

exception core-file

To specify the name of the core dump file, use the exception core-file global configuration command. To return to the default core filename, use the no form of this command.

exception core-file nameno exception core-file

nameName of the core dump file saved on the server.

DSL VS Cable Modem

The most common question we get in DSL vs Cable Modem discussions is which service is faster? Cable  download speeds are up to 2 times faster than 1.5Mbps DSL about 50x the average speed of a 28.8K Modem.

Restrict network access by time or IP address with Squid

There are a number of reasons why you would want to restrict network access. You run a cafe with web access or you have young or teenage children and you want them to only be able to use the network at certain times. Their are certainly tools out there to do this on a PC-by-PC basis, but why not employ a proxy server instead? One of the best (and most robust) proxy servers available for the Linux operating system is theSquid Proxy server. But don’t let the name fool you, you do not have to install Squid on a server. You can just as easily install squid on a Linux desktop machine and control network access from your LAN.
Of course when you open up your /etc/squid/squid.conf file you might be a bit overwhelmed. So in this article I am going to show you two ways to limit access with Squid (instead of tossing the whole configuration file at you at once). I will also show you the quick and dirty method of installing Squid on a Fedora 13 machine. Once done with this article, you will at least be able to control network access by time or by IP address. In later articles we will discuss other ways to control network access with Squid.

Vinagre remote desktop connection for Linux

Do you administer Linux machines? Or do you just need the ability to remotely connect to your Linux machines from other Linux machines? If so, are you looking for an easy solution for this task? There is one, if you are a fan of the GNOME desktop.
Vinagre is a remote desktop tool with plenty of features and ease of use for just about any level of user. It’s enjoying release 2.30.1 so it’s quite mature. In this article I will show you how to install and use the default GNOME remote desktop tool.
Vinagre offers enough features to help make it stand out among other rdp clients:

See what images are being viewed on your network with driftnet

I want to preface this article by saying I am not, in any way advocating spying on your users. With that said, there are times (and reasons) why you might need to see what images are being viewed on your network. Whether it be an end user who is viewing content that goes against specific company policies or, worse, against the law. When this happens, you might have need or cause to see just what is being viewed from your LAN. When this is the case there is a handy tool for that called Driftnet.
Driftnet was inspired by the old Apple program EtherPEG and works by watching TCP streams for images and MPEG audio streams. As it listens I dumps the images into a user configured directory and/or it can display the images within a window as they are captured. In this article I will show you how to install and use Driftnet.

Connect remotely from Linux with Terminal Server Client

I do a lot of remote work throughout the day and to make those connections I use different tools. Between LogMeIn andTeamViewer I have remote support covered. But when I need to connect to a machine such as a Terminal Server, where do I turn? Generally speaking I turn to the Linux tool Terminal Server Client (tsclient.) This tool makes connecting to unattended remote servers a snap — and it workswith different protocols.
Just what does tsclient offer? Take a look at this short list of features:

Network Troubleshooting Basics: Tracert & Pathping

This article is the third in a series of the basics of network troubleshooting. So farping and ipconfig have been covered. Now tracert and pathping, which are similar commands, will be covered. While this is a basic tutorial, there are some intermediate tips and topics included. The focus will be on Windows based systems(with a tip or two for other systems).
Both of these commands are designed to give you more detailed information than the ping command. They will tell you about steps along the way. This can help you narrow down where a problem is.

The Tracert Command Basics

The tracert command is also called traceroute on other systems, such as on a Mac or in Cisco’s IOS (used in its routers and switches). It is used to find out what other devices are on the path to a destination. It works by sending out a number of signals. Each signal has an amount of locations it can jump to, called a time to live (TTL).