Monthly Archive for April, 2007

Setting up a Linux Bridge

Published
by
Zz85
on April 11, 2007
in Technology and linux
. 3 Comments

Mentioned in MIO is here, at last, I needed a bridge to trick/configure the router into recognising my 5th cat5e/ethernet wired pc.

A network bridge (before my cisco networking license and memory end soon)
* Connects 2 or more networks together
* Usually transparent in a network (unless an interface is created, like in a firewalled bridge, like in this case)
* A layer 2 device- less lag when compared a router (a layer 3 device) and therefore faster(?)
* Same broadcast domain, same subnet address
* Different collision domains, preventing the networks to split the wire’s bandwidth.

Here is a script I used to test out if my bridge could work

#bridgeman.sh
# Create the interface br0
/usr/sbin/brctl addbr br0

# Add the Ethernet interface to use with the bridge
/usr/sbin/brctl addif br0 eth0
/usr/sbin/brctl addif br0 eth1

# Start up the Ethernet interface
/sbin/ifconfig eth0 0.0.0.0
/sbin/ifconfig eth1 0.0.0.0

# Configure the bridge Ethernet
# The bridge will be correct and invisible ( transparent firewall ).
# It’s hidden in a traceroute and you keep your real gateway on the
# other computers. Now if you want you can config a gateway on your
# bridge and choose it as your new gateway for the other computers.
/sbin/ifconfig br0 192.168.1.66 netmask 255.255.255.0

run chmod +x bridgeman.sh

Note that the last line in the script was fairly important as I configure my router remotely via ssh. I first time I tried configuring a bridge, I added no interface the bridge, so by the time enabled the bridge interface, the linux box became transparent to the network and my ssh connection was dropped (that is different of course if you are configuring at the local terminal).

This is the configuration I used in /etc/network/interfaces for automatic startup/restart situations

# The bridge network interface(s)
auto br0
iface br0 inet dhcp
       bridge_ports eth0 eth1

Links
http://linux-net.osdl.org/index.php/Bridge
http://www.debian.org/doc/manuals/securing-debian-howto/ap-bridge-fw.en.html

http://forums.invisionpower.com/index.php?showtopic=187910
http://compsoc.dur.ac.uk/~djw/qemu.html
http://affix.sourceforge.net/affix-newdoc/Affix-enduser/x199.html

InTell GPS-009: To buy or not to buy?

Published
by
Zz85
on April 5, 2007
in Technology and Thoughts
. 0 Comments

Thats the question. For now.
InTell GPS-009

A bluetooth GPS receiver. Although it seems like this was sold for $109 at the IT show, Eastgear is selling for $159 bundled with Singapore and Malaysia MapKing for PocketPCs ($99 each usual price). This promotion seems to be for the new unit moving away from Peninsular Plaza.

Points for consideration
- So far the cheapest GPS device I ever seen (other that the PSP GPS adaptor which cost about $90).
- Looks not too bad. Shaped like a ipod nano and its quite slim
- for $160, I could buy 16 maps of different areas from Popular bookstore. I must visit and use this at more 15 countries to make it worthwhile.
- at this price I could buy a Polar footpod. If this could be use for my jogging/cycling distance, its something worth considering.
- Usage of bluetooth allows flexibility - use it with a PDA, Laptop, PC or Handphone. The thing is that I would have to use it with the last and there will be certain limitations software wise.
- Singapore’s not a big country. Do I need $160 to tell where to turn left or right?
- How efficiently would this work? Esp. in urban built up areas.
- $160 issnt too little, nor too much (no feeling after spending $$ much lately) There are other opportunity costs for this.

NDS Lite vs PSP

Published
by
Zz85
on April 4, 2007
in NDS and Updates
. 0 Comments

Why I chose the Nintendo DS lite (NDS Lite) over the Sony Playstation Portable (PSP).

Its seemed like a long month in May. I was spending more on projects in Camp, but my concentration is definitely drained elsewhere. It wasn’t duties, so maybe music, maybe something else.

May is a month lots of money spent, on gadgets mainly, perhaps kicked off by the IT Show.

So I bought a NDS Lite -this will be added to my memories of hand-held computer games I bought in my life (I could count all of them with my fingers) since young.

While the majority of people I know owns a PSP, and rare minority an NDS, why the latter for me?

Here’s my reasons. NDS..

- Seemingly cheaper (~$230 vs ~$300)
- More portable (Easier to carry around or place in the pocket)
- Longer Battery Life
- Touchscreen (With a stylus, even 2)
- Although hardware’s power no where near the PSP, games are more creative and innovative (hardware usually fully utilized)
- Interesting homebrews
- DS sales wins high over PSP
- Comes in nicer colours

In no way here I’m looking down on the PSP. The points above are mostly debatable, eg. price of the PSP is quite low now (and getting even lower after a recent news says sony will cut down another 15% due to low sales). For its powerful hardware and features, its hard to beat. Tons of quality homebrew / hacks are available for the PSP.

For advice I would say, take the PSP if you want the entertainment (nice screen, graphics, and music) but pick the DS if you want something special, innovative or classic.

See this link which had a big influence on me for buying the NDS. Maybe this might affect you another way.

MIO is here, at last.

Published
by
Zz85
on April 4, 2007
in Stories and Technology
. 6 Comments
I signed up for the value plan of $68 for internet, home and mobile lines each month. Below is my first day experiences plus the changes that affected me.

So finally, MIO was scheduled to arrive today, and the home telephone line got cut off for its conversion into digital voice. I took off the whole day especially for this (actually plus other events planned but got canceled due to wet weather). A mio personnel was supposed to be here at the given time slot, but he was extremely late. I had to go out, and later I had to provide him my singnet login details over the phone.

The most significant change will be the “MIO Box” or actually a 2wire 2700HGV-2 router with a customised/restricted singtel/mio firmware. Not too bad actually, supports ADSL2, 4 ethernet ports, usb connection, line, VoIP, 802.11g, except maybe its bigger and runs warmer. I soon know the restrictions of the router, or maybe its firmware. I know I can update the firmware to unlock more features, but I resisted the temptation of such risks even though I thought I’m capable of doing it.

So hit http://gateway.2wire.net/ or 192.168.1.254 to log into the router. I differences and adaptations I had to do from my previous router- the netgear dg24m are-

* Different router address/subnet. I attempted to configure the 2wire router to retain my old subnet but it refuses. Time to redesign my home network.

* Navigation and settings are shown in an easier, more “user friendly” style, icons and such, but seems its a different way of configuration compared to usual routers and advance configurations seems to be lacking.

* Doesn’t allow me to add a static route, or add another network, which means, to allow another router to work together. The solution? Reconfiguring my linux router into a linux bridge with an interface (aka firewalled bridge). See my next post for details.

* Doesn’t provide updating of dynamic dns services like DYNDNS.org. I decided to install ddclient on my linux server in this case.

* Doesn’t seem to support uPNP for port mappings and such.

* It should support port forwarding (described with a different term on the 2wire router) but I haven’t seem to be able to get it to work.

I stop here with this list about the MIO Box temporary.

At for its unlimited voice call service, I have yet to find out where the bad interfaces I hear during calls come from. 1) MIO Line 2) Old Sanyo Analog cordless phones 3) new philips DECT phones

So much for now.