Extending wi-fi signal of an ADSL-modem-router using a Virtual Server and a bridge (two extra routers)

First of all, what was the problem:

I needed to extend the wi-fi signal range of the ADSL-modem-router given by MTNL (our ISP) so as to reach a room that is really far from the source, but we need it to be there.

I tried and tried, but could not make a simple bridge as I had done earlier ( http://jamodiy.blogspot.in/2010/08/set-up-router-as-repeater-bridge-to.html )... it seems the problem is that the device given by the ISP does not allow itself to be bridged! I tried with several routers, of different brands, and after many hours of attempts I came to that conclusion.

Since I have several spare routers, I thought of trying bridging the modem with a wired router, and then bridge that router through wireless with another router. It took many, many, many hours of work, but finally managed to do it, and here are the settings I've used:

FIRST STAGE

1. MTNL ADSL-modem-router is a model 450TC1... it should be connected and working, and then, start changing settings (or ensuring these settings are there).

Interface Setup

2. LAN:  Dynamic Route: RIP2-B ; Direction: Both; Multicast IGMP v1; Physical ports: All checked

3. Internet: As per ISP

4. Wireless: As per your usual wireless network settings (it shouldn't make any difference to the rest of the network).

Advanced Setup

5. Firewall: Firewall: Enabled; SPI: disabled

6. Routing table: I'm not sure if I did anything on this, so just in case, screenshot:

7. NAT, QoS and VLAN Group: Here is where I did several changes. I'm not sure of which changes where the right ones (trial and error), but I think the most important matter is the one related to the Virtual Server (should be, right?). And the VLAN Function should be "Activated"

8.Access Management: I did no changes here.

SECOND STAGE


9. Now, switch on your second router to the power supply, and to your computer, but not to the first router. In my case, I'm finally using a PRONET router model PN-11NWRT.

10. Go to the LAN settings and change the IP address. Ensure that it is a different subdomain from the LAN of your first router. In my case I've used 192.168.0.1 . Notice the zero marked in red, instead of the usual 1. Reboot this router.

11. Go to the WAN settings. The WAN connection settings should be "Dynamic IP". This means that when you connect this router to the first router, the first one is going to assign it an IP which will be seen as the "Internet connection". That's the importance of keeping a different domain for this separate LAN.

12. In the Wireless Settings, ensure you define a channel, say Channel 1 (this would be important to remember for your bridging afterwards). Don't leave it Auto.

13. Define your wireless security... depends on the other router you will use, but in my case I've used WPA-PSK/WPA2-PSK. Obviously, remember your password, as you will need it also for the bridge.

14. The DHCP must be ENABLED. Remember that this second stage router is creating a second LAN, therefore it will have to assign IPs to any computer or device that might connect through the second or third router to the network.

THIRD STAGE

15. Now, switch on your THIRD router to the power supply, and to your computer, but not to the first nor to the second router. In my case, I'm finally using a TP-LINK  router model TL-WR740N.

16. Go to the LAN settings and change the IP address. Ensure that it is the same subdomain of  the LAN from your second router. In my case I had used 192.168.0.1 in the second router, and for this router, I've used 192.168.0.10 . Notice the zero marked in red, instead of the usual 1, and the 10 as the last digits. Reboot this router.

17. The rest of the process should be same as in my previous post related to this: http://jamodiy.blogspot.in/2010/08/set-up-router-as-repeater-bridge-to.html ... Just ensure that the Channel is the same as you had chosen in step 12 above, that you enable the WDS settings, and that you disable the DHCP.

FOURTH STAGE

18. Now, you've got all the soft-configurations... now you have to think of the position of your routers... The second router needs to be near enough to the first for the wire to connect each other. And the third router needs to be near enough to the second in order to catch the wireless signal and bridge it accordingly. Play around with the position of your routers and get as far as you can with your signal!

If there are people concerned about the good lookings of your house, you may not be allowed to leave things the way are down in the picture, and you'll have to work on hiding the cables, etc... but that's a separate topic!

Warning: There are some routers that cannot be bridged, or cannot act as bridges. They simply do not have the inbuilt capability. To discover that you can only do it by trial and error... with many hours of work. It happened to me in this case with a NETGEAR router model WGR614iS... great signal, but no bridging! :(

Print Align Cartridges page from Control Panel

I take this info from the HP web-site, but I paste it here just in case they remove it and I (or somebody else) need it in the future.

To see the original at the HP site, click here.

Aligning Ink Cartridges

Printing an alignment page using the printer control panel

If you are installing a new print cartridge, the product begins to print a print cartridge alignment sheet. This may take a few minutes, if the alignment page is not printed follow the steps below to print an alignment page using the printer control panel.

1. Press and hold the Cancel button, and then press the On button. Then release both buttons.
2. Press and release the Cancel button.
3. Press and release Photo (Paper Type).
4. Press and release Color Start Copy . An alignment sheet prints.

Once the alignment page is printed, follow the steps below to complete the alignment process.

1. Lift the lid of the product.
2. Place the top of alignment page face down in the left front corner of the glass.
   Figure 2: Place the alignment page face down

   
3. Close the lid.
4. Press the Scan button.
5. The On light will blink during the alignment process.
6. After the On light stops blinking, alignment is complete.

Basic cell phone signal booster

I have shifted to work in an office within a basement... obvious consequence: low cell phone signal, battery drainage, missed calls and calls that get cut.

I wanted to try out a cell-phone signal passive repeater, but for that you need 2 antennas, and so far, I've been able to get only one. But it is already helping me!

It is a small antenna from a surveillance system with wireless cameras (picture below).

With this small antenna, I just have to open the receiving plate, place my cell-phone right in front of it, and in a matter of a few seconds, the signal goes from practically null to about 80%. 

This helps only for avoiding battery drainage and missed calls, because once you move the cell-phone far from the antenna (i.e. when you speak on the phone during a call) the signal again reduces a lot... but is quite some help for something that took no effort at all.

I hope I manage to get another antenna so as to try out the passive signal repeater soon.

Standard password for Airtel modem 220BX

The other day I spent some time trying to figure out what was the password to reach the configuration of the modem so as to be able to install a wifi network (http://jamodiy.blogspot.com/2011/04/connecting-wireless-router-to-switch-to.html).

Finally, after some time I came across this other web-site which game the answer:

Username: admin
Password: password

Connecting a wireless router to a switch to an Airtel ADSL modem

When I arrived there was no wireless network here. The Airtel ADSL modem was distributing the wired network to all computers through a switch.

It took me sometime to find out how to do this until I came across this information on how to connect a router to a router:

Suppose you have an ADSL modem with a four port router (e.g., a D-Link DSL504 ADSL Modem/Router or 2Wire 2701HGV-W). You've bought a second router (e.g., a Belkin 54Mbps Wireless 802.11g) and want to plug this into the network to add in and to share more local machines, and to share the Internet connection. Let's refer to the first ADSL router as router A and the second as router B.

Configure router A to issue DHCP addresses in some range that does not include one IP address that we will use for router B For example, router A might only issue IP's in the range starting at 192.168.0.2 and ending at 192.168.0.33 and we'll configure router B with 192.168.0.40. This is all the setup that is required for router A, which otherwise has DHCP enabled and its usual WAN setup for your ISP.

Disable DHCP for router B, and configure its WAN (Wide Area Network) type to be STATIC and set it to any IP (e.g., 192.168.111.2--should be different to the A network), with a netmask of 255.255.255.0. Specify a gateway IP of 0.0.0.0 (or perhaps 192.168.111.1, if your router will not allow 0.0.0.0). This will stop it sending traffic to its WAN (we won't be using this router's WAN connection).

The LAN (local area network) configuration for router B should be set to STATIC with an IP address within the subnet range of router A but outside its DHCP range. We might set the LAN IP to 192.168.0.40 (or 10.0.0.137) with a Subnet Mask of 255.255.255.255 (or 255.255.255.254 perhaps if that doesn't work) and with DHCP Disabled. In fact, router A will serve as the DHCP server for anything connected to router B.

Make sure that nothing is plugged into router B's WAN. Connect a LAN ethernet port of router B to a LAN ethernet port of router A to have them talking to each other, using the usual ethernet cable that you would use to plug your computer into the router.

Source: http://togaware.com/linux/survivor/Router_Router.html

Although the Airtel ADSL modem 220BX I have here is not a router, it is the one providing the DHCP, therefore, it should be treated as if it was the router itself.

Keep in mind that the switch is a totally passive device and there is no configuration you have to do on it.

The only change I had to do with respect to the information from togaware.com is that the Subnet mask for the network of router B couldn't be 255.255.255.255, or 254, but had to be 255.255.255.0, and I had no problem about it.

Also, it could be a good idea that you assigned static IPs to the computers and laptops that will be connected through the wifi network, otherwise there maybe some IP clashing with the wired computers (as the wifi network is getting IP assignment from the modem, but is not included in the DHCP list).

Make HP printer think there is a new catridge after catridge refill

I read this information:

While a Hewlett Packard (HP) inkjet cartridge can be refilled easily, getting it to work again in the printer is another matter. The contacts on the back of the cartridge are programmed to read the ink level, but they don't reset for the printer just because you add more ink. You must get the printer to recognize the cartridge as new. You can do this easily if you have two other old cartridges, or you can manipulate the contacts on the refilled cartridge.

Difficulty: Moderate

Instructions

Things You'll Need:

• Adhesive tape

1. Insert the cartridge you refilled into the HP printer. Have the printer print an alignment page, thus recognizing the cartridge. The printer will still read the ink level as where it was before you refilled it.
   
2. Remove the cartridge from the printer and replace it with another old cartridge. Have the printer print an alignment page with this cartridge so it recognizes it as a different cartridge from the first one.
   
3. Replace the second cartridge with a third one and run the same alignment page. Because the printer only retains the memory of two print cartridges, it will erase the memory of the first (refilled) cartridge.
   
4. Insert the refilled cartridge into the printer. The printer will now recognize the cartridge as being full.

1.  Second option:
    1
   Tape over the contact squares on the top left corner of the cartridge's contacts. Insert the cartridge into the printer and run an alignment page. Ignore any messages that might appear saying there is a problem with the cartridge.
   
2. 
   
   Take the cartridge out of the printer. Remove the tape from the left corner and tape over the contact squares on the top right corner. Place the cartridge back in and run another alignment page.
   
3. 
   
   Remove and reinsert the cartridge, this time with no tape on any of the contacts. Check to see if the printer recognizes the cartridge as being full.
   
4. 
   
   Repeat the above steps if the cartridge is still shown as being empty. This time, use the bottom corner contact squares instead of the top ones. If you are still unable to reset the cartridges, using multiple cartridges is likely the only way to do it.

In my case, I only have two cartridges, so I did a combination of both techniques. I put the old one (without ink), then the same one covering some of the contacts with tape, then again the same one, covering other contacts... finally the refilled cartridge... and it seems to be working!

By the way, I have an HP Deskjet F4185

Scan and send a signed contract as PDF

After signing the contract, you scan the pages, and each of them will come to you as jpeg (or some other format) image file.

Then, print to pdf each of these images. Now, you have a bunch of PDF files.

If you have ubuntu, then you can merge the pdf files into one, using these instructions:

http://ubuntuhowtos.com/howtos/merge_pdf_files

First of all you will need the program called pdftk. You can get it by opening terminal and typing:

sudo apt-get install pdftk

Now you can merge pdf files by putting them in the same directory and typing:

pdftk 1.pdf 2.pdf 3.pdf cat output merged.pdf

or if you wish to merge files in alphabetical order you can simply type:

pdftk *.pdf cat output merged.pdf

If you use this last command, make sure you don't have any other files there in pdf format which you don't want to be merged with your contract (or any other document, of course).