Archive for the ‘ Internet ’ Category

OpenSWAN

Lately I’ve been playing with OpenSWAN and IPSec in general.

For the last few years I’ve been using OpenVPN as my home VPN server, but recently I bought a few Intel PRO/100 S Server Ethernet adaptors. From looking on the Intel site the only big difference I could see between these and regular Intel PRO/100 cards was that it has IPSec offloading, which I also remembered seeing IPSec support on my iPhone. So that got me looking into replacing OpenVPN with OpenSWAN on my home router.

In the past, I have come across IPSec quite often, but I never really looked into it. After a bit of reading, I decided to buy “Building And Integrating Virtual Private Networks With OpenSWAN“. I haven’t finished reading the book, but I can say that it is a very well written book for people looking to get started with IPSec. It has quite a nice introduction on the internet and why encryption is so important on the internet. It also explains how encryption was originally only used by the military and how governments around the world tried to stop encryption being used widely across the internet.

On Linux, there are two IPSec stacks, NETKEY and KLIPS. KLIPS is currently the more stable one, and from what I understand, the one which is easier to use. NETKEY on the other hand, is quite a new stack, but due to various reasons, KLIPS was not allowed to be included in the Linux kernel by default, where as NETKEY is.

Since my router machine is running RedHat Enterprise Linux 5, which only includes support for NETKEY, I have been using the NETKEY IPSec stack. So far, the only problem with the NETKEY stack is that creating firewall rules for encrypted packets is much more difficult than it would be using KLIPS, although I was not too disapointed by this since the KLIPS does not have IPv6 support, which, since I like IPv6 so much, is a must for me! :)

Although I had a bit of a problem with the OVH kernel, after a bit of tweaking and compiling and a lot of rebooting, I was able to create an encryted tunnel between my OVH RPS and my home router. If it had not been for all the trouble I had with the OVH kernel (it took quite a while to get the RPS to boot from the iSCSI disk using my custom kernel, rather than use netboot to fetch an OVH kernel), the tunnel would have been set up within a few minutes, which I found amazing as it takes a bit more time and effort to do with OpenVPN.

So far, I haven’t managed to figure out how to use the IPSec offloading feature of my ethernet cards, but I don’t think thats is really a problem considering my router machine is powerful enough to handle the few IPSec connections that I  have setup (Its a 2.4GHz Pentium 4 machine with 1GB ECC Reg RAM).

After a bit more reading, I decided it would be fun to try and get my iPhone connected to my IPSec Server, so over the next few days, hopefully thats what I will be doing! :)

Facebook!

After three or four quite useless posts, I thought it might be time for a “real” post, so here it goes! :)

As everyone might know, Facebook have rolled out the new layout and have removed the old one. In a final “fight” to use the old one, A LOT of facebook users joined the Facebook developers group, only to find that the old layout has been removed completely (as far as I know).

A lot of people think that there was not any “real” problem with the old facebook but the issue with the old layout that triggered the need for a new layout was the fact applications were shown on one page. This meant that some pages became VERY cluttered for the users who seemed to add every application available!

In my opinion, the main reason Facebook is such a sucessful site compared to other social networking sites is that it is neat. If you look at Hi5, MySpace, BeBo, they all use quite flat pages (very little to no AJAX!) which the user can modify the layout of through the use of CSS.

Most normal users would tell you they would LOVE to be able to customise the look of their profiles on Facebook, but most geeks would probably cringe at this idea. Why? Most people who use such social networking sites don’t really know much CSS or HTML, so they write bad CSS and create horrid pages which take way too long to render and sometimes even crash the browser.

Users who add too many applications are in effect doing the same thing. There are too many things to render (images, text, colours, sometimes even flash!), and so your over all Facebook “experience” is brought down to something which is not so plesurable.

Although most people may be thinking that the new layout gives them a worse experience, I’m pretty certain, it is much better than having cluttered profile pages which sometimes crash your browser :) .

I will accept that the new layout COULD be better, but there is no doubt about it, the new layout beats the old one overall.

BT!

BT finally fixed my telephone line! :D

Apparently there was a faulty cable going from the “cab” to the poll that provides the overhead cable into my house, so the guy just switched that, and now its all working great :D . My SNR is a lot more stable, and my connection hasn’t dropped since Monday :D . Another thing I noticed was that my
attenuation is lower than what it was :) .

Total Available Bandwidth           Cells/s           kbit/s
Downstream                 :     19308             8187
Upstream                   :      3125             1325

Bearer Generic Info               Downstream        Upstream
INP          (DMT)           :         6.23             0.00
Delay        (ms)            :         6.03             0.24
R                            :        16                0
Margin       (dB)            :        18.0              7.0
Attenuation  (dB)            :        14.0              6.0
OutputPower  (dBm)           :        18.0             12.0

Switching to O2 Broadband

As some of you might know, I recently switched from VirginMedia (Cable) to O2 Broadband (ADSL).

To do this, I had to get my BT Telephone line enabled, and my VirginMedia Telephone line canceled.

Although this seemed like an easy task, it was actually more difficult than I had expected.

I wanted to keep my old telephone number that I was using on my VirginMedia line, so BT had to do some number porting things which they said should take 1 week or so. So I waited, and after 1 week, it had not been done! In the end I had to wait 1 month for it to be done.

When the number had finally been ported, there was something strange up with the actual line, and I couldn’t get a dial tone, so a BT engineer had to come around and check it out. He fixed it, but he noticed that there was a lot of noise on the line (crackling sounds). After a bit of tweeking, the noise was bareable, but I wasn’t really fully pleased with that, as it would cause a problem with my ADSL connection once it was activated. Funnily, the noise isn’t there all the time, it is there very faintly at some times of the day, and VERY heavy at other times.

Anyway, I called up O2 and ordered the connection, and after a few days my line was activated and ready to go! BUT, I soon found out that everything was not as good as it seemed.

Whenever the phone rings, or the noise is high on the telephone line, my internet connection dropped and the modem had to re-sync, which takes a while. This sucks since I am an IRC user and I also host an IRC server. Every time the connection dropped, I pingout from all the servers I am connected to, and so does everyone who is connected to mine.

So after a bit of investigation (testing in the master test socket, changing filters, trying a different phone etc), I came to the conclusion that the noise on the line is the only thing that could be causing the disconnections. So I called up BT, and they sent an engineer to check it out, BUT the noise was VERY faint at that time, so he had to leave without doing much, (he checked all the connections where he could etc, but understandably that was all he could really do if the noise wasn’t there at the time).

Even after his checks, the noise is still currently there, so I am having to call BT up again. They told me they will send another engineer around who will check it out and hopefully the noise will be there when he gets here. I don’t know how long this will keep going on for, (an engineer coming to check it out, then leaving cause its not there at that time etc).

Hopefully this problem will be resolved soon as it is driving me insane!

Until then, if anyone has any ideas that may help, please comment! :)