测试你的宽频公司有“限制”你的BT吗？

BT下载好慢！

今天就介绍大家一个网站，可以检查看到底你的宽频公司有“限制”你的 BT 吗？！但，让我先说说什么是 BT？

（可能有一些人还不知道什么是 BT，哈！<--- 应该很少人不知道了吧...不知道自己在说什么，怪怪地）

BT 是 Bit Torrent 的缩写，相信大家都非常熟悉和常用的一种软件。BT，在网上俗称“变态下载”，是一种运用P2P的概念来互换资料和文件的软件。它，不再想 FTP 或 HTTP，甚至是 MU 似的只靠一个或几个服务器为发源地。这种 BT先进的下载方式减轻了服务器端的负荷，同时加快了客户端的下载速度。它采用的是人人电脑都是服务器的概念即P2P（Peer-to-Peer），下载的人越多，共享的人越多，下载的速度也越快。

很多时候，宽频公司（ISP）为了不要“浪费”他们的宽带（Bandwidth）都会控制减少 BT 的速度或更甚的是完全“抹杀”了 BT 的“交通”！本人在大马就知道一些 ISP 有这么做，如 M 字头的，T 字头的就视地区和帐号而决定和等等。也有一些本地的 ISP 则蛮大方的....嘻！

Test if your ISP is manipulating BitTorrent traffic

http://broadband.mpi-sws.mpg.de/transparency/bttest.php

 

此外，这网站也提供了测试你宽频的速度：

Test your broadband link

http://loki07.mpi-sws.mpg.de/bb/bb.php

看看我的测试结果:

**以上的测试结果是用不同的宽频公司来测试的...

分享记得一下你的测试结果哦！

Googolopoly<--Google的百万富翁?

Google = Googlopoly ?

有用电脑上网的人，可以说无人不认识Google（谷歌）。Google本身也可以说是个成年人的Lego+Ikea游乐场。为什么那么说呢？Google的“软件发展”可以说是没有限制，没有任何阻止的空间。它，任由你去发挥，天马行空的想法...

Google Labs, 就是你的科技游乐场！所谓的 Technology Playground！

 

最近在网上发现了一个新的“概念”，就是Google百万富翁！（Googolopoly）。设计的人就是想表达说，Google的经营说法就好像在玩百万富翁似的。Google一直都在资讯世界里，一直尝试并企图地在改变和控制资讯世界（Information World）。让一切一切其他的“玩家”跟随它的想法和概念！到底将来如果是Google Revolutions Information World会是一件好事吗？

如果你觉得是不关你的事，那么就不要想那么多...下载这个Googolopoly来看看，也可以玩玩哦！

按此下载 ( Click to Download )

Google Apps

听同事说有关Google Apps的好处很久了，他说真的很方便，还说以后“我们”会没有工作了...人们+公司不需要 Network Admin了，大剂！

一直都没有时间去“研究”，又不敢拿我原本的 Domain + Hosting 来“搞非”。担心一搞，就更加多工，最惨是可能 Data 会不见...昨天，终于帮友人弄了一个 Domain。

原本打算到本地公司如 Exabytes 或 Shinjiru 或我现在的 Domain hosting company --> eMerge 开创的，哪里知道普通的 .com 价钱也比其他来的贵，便宜的，procedure 和 payment method 又麻烦，真是的！最后，还是到了国外的 godaddy.com 开创了，从开始游览到开创成功 + host 在 Google 前后只用了少于一个小时！！你说容易吗？

Google Apps 的配套

Free Edition

• 价钱 : 免费
• 内容：Gmail, Google Talk, Google Calendar, Google Docs, Google Sites, 和 Start Page
• 电邮的容量：到今天为止是 6.675337 GB / 户口
• 自行 manage 的介面和更多的 features....参阅这里

很不错的网上服务！值得一试！！

IP Addressing/Subnetting : Chapter 3

After the tutorial and discussions in Chapter 1 and Chapter 2, I believe most of you should have an better idea on the IP addressing/subnetting. Now it's the time to apply the knowledge on some problems analyzing and designing.

Q : If you are given the situation below, and you should "separate" your network as accordingly. What should you do and how is the IP assignment?

Network ID : 203.158.30.0

Subnet Mask : 255.255.255.0

Number of networks needed : 4 different separated network

First of all, you need to know the total number of hosts available in the network given. Total number of IP address available

= ( 2 ^ unmasked bits ) - 2

= ( 2 ^ 8 ) - 2 = 256 - 2 = 254 hosts if default Class C is used

Divide the network into 4 different network, each network should have ( Including every network ID and broadcast IP )

= 256 / 4 = 64 hosts each

Thus, your subnet mask for each network

= 255.255.255. [ 254 hosts - 64 hosts each ]

= 255.255.255.192

Now, it is the time for you to "chop" your 203.158.30.x network. Your may get your Network ID for each network by adding 64 hosts each started from .0

The Broadcast IP for each network will be next Network ID minus 1 as shown in the "chop" diagram below. What remaining in between the Network ID and Broadcast IP are the available IP addresses can be used.

=== 1st Network ============================================

203.158.30.0 -------------------------------------   Network ID

203.158.30.1 ~ 203.158.30.62                    Available IP addresses

203.158.30.63 -----------------------------------    Broadcast IP

=== 2nd Network ============================================

203.158.30.64 ------------------------------------   Network ID

203.158.30.65 ~ 203.158.30.126                 Available IP addresses

203.158.30.127 ----------------------------------    Broadcast IP

=== 3rd Network ============================================

203.158.30.128 ----------------------------------   Network ID

203.158.30.129 ~ 203.158.30.190               Available IP addresses

203.158.30.191 ---------------------------------    Broadcast IP

=== 4th Network ============================================

203.158.30.192 -----------------------------------   Network ID

203.158.30.193 ~ 203.158.30.254                Available IP addresses

203.158.30.255 ----------------------------------    Broadcast IP

Now, you may try yourself on solving the question below.

Q : If you are given the situation below, and you should "separate" your network as accordingly. What should you do and how is the IP assignment?

Network ID : 192.168.4.0

Subnet Mask : 255.255.254.0

Number of networks needed : 16 different separated network

In the next post, I will continue in the C.I.D.R. Have a nice day~

IP Addressing/Subnetting : Chapter 2

Further to the previous post ( IP Address/Subnetting : Chapter 1 ), before I go into the topic, let's me get some FAQs.

Q: What is Network ID?

A: Network ID is an "identifier" of a network when you are trying to tell others what network/subnet are you ( sounds profesionally?! ) rather than telling the whole story, IP address, subnet....blahhhh...

Q: What is broadcast IP ?

A: Broadcast IP is normally the "last" IP of a subnet addresses. For example, 192.168.1.255 is the broadcast IP for default Class C ( 255.255.255.0 ) 192.168.1.x network. If a packet is addressed to the broadcast IP, then it will be targeted to EVERY stations in this particular network. That's why it's called broadcast IP.

Q: Why should I know IP addressing/subnetting ?

A: It is very important someday when you need to design and implement a network, you may need to know how to consider the appropiate subnet mask to be used and numbers of hosts you may have when a subnet mask is used. In addition, it is also very important and useful when you do the network routing and NAT-ing as well as firewall ruling.

Q: How many hosts in a Default Class C ( 255.255.255.0 ) network ?

A: A Class C network have 254 hosts. It can be simply calculated using a formula by considering the subnet mask and number of binary bits.

Default Class C would have binary of

1111 1111. 1111 1111. 1111 1111. 0000 0000 = 255.255.255.0

We can just consider the number of 0s in the subnet mask ( It is known as UNMASKED BITS or SUBNET BITS ) and convert it to 1s which are 0000 0000 = 1111 1111, by refering to the chart below :

The SUM of unmasked bits

( 1111 1111 )

= 128 + 64 + 32 + 16 + 8 + 4 + 2 +1

= 255

Because of the first number of an octet is started from 0 instead 1, therefore the total available IP address would be :

= ( SUM of Unmasked bits ) + 1

= 255 + 1 = 256 IP Addresses

By using the formula Total Available IPs minus 2, the result will be the total number of hosts in default Class C network :

= 256 - 2 = 254 hosts.

EXAMPLE 1

Network ID : 10.10.10.0 / Subnet Mask : 255.255.255.192

1111 1111. 1111 1111. 1111 1111. 1100 0000 = 255.255.255.192

Total Available IPs = ( 32 + 16 + 8 + 4 + 2 + 1 ) + 1 = 64

Thus, the total number of hosts = 64 -2 = 62 hosts

For Network ID : 10.10.10.0 ,

Thus, the broadcast IP = x.x.x.0 + 64 IPs = x.x.x.64 = 10.10.10.63

EXAMPLE 2

Network : 10.133.80.32 / Subnet Mask : 255.255.255.224

1111 1111. 1111 1111. 1111 1111. 1110 0000 = 255.255.255.224

Total Available IPs = ( 16 + 8 + 4 + 2 + 1 ) + 1 = 32

Thus, the total number of hosts = 32 -2 = 30 hosts

For Network ID : 10.133.80.32 ,

Thus, the broadcast IP = x.x.x.32 + 32 IPs = x.x.x.64 = 10.133.80.63

Anyway, besides using the standard formula above ( which you may need to know but not neccessary to remember it :p ) There is another CHEAT FORMULA as below :

Referring to Example 1 again :

Network ID : 10.10.10.0 / Subnet Mask : 255.255.255.192

Then use the formula :

Total IP available = 256 - last subnet mask portion

= 256 - 192 = 64

Then continue to the other formulas to get the Network ID, number of hosts and the broadcast IP as above.

ALTERNATIVELY:

You can use to calculate the number of hosts is = 2 power of ( unmasked bit )-2, in this case :

Total number of hosts = (2 ^ 5 )-2 = 62 hosts

As reminder again, please always remember that :

1. The FIRST IP in a subnet = Network ID
2. The LAST IP in a subnet = Broadcast IP
3. Remaining IPs between item (1) and (2) are the available IPs can be used in the network devices e.g. PC, router etc.

As reference, the graphical charts below shows the number of hosts for 10.0.x.x network with different subnet mask & unmasked bits.

Let me discuss on another example, this time we are given an IP address and subnet mask instead of Network ID is given :

EXAMPLE 3 :

IP : 10.20.237.15 / Subnet Mask : 255.255.248.0

In the case to get the Network ID, 0s in the subnet mask will convert whichever number from IP address into 0.

0000 1010. 0001 0100. 1110 1101. 0000 1111 = 10.20.237.15

1111 1111. 1111 1111. 1111 1000. 0000 0000 = 255.255.248.0

---------------------------------------------------------------------------------------------

0000 1010. 0001 0100. 1110 1000. 0000 0000 = 10.20.232.0

Network ID = 10.20.232.0

The FIRST IP : 10.20.232.1

The LAST IP

= 10.20.[232 + (8 unmasked bits in subnet mask portion 3) - 1].255

= 10.20.232.255

Number of hosts = (2 ^ unmasked bits) - 2 = (2 ^ 11) -2 = 2048 hosts

( which equivalent to 4x default Class C network )

Try it out yourself....and I think I should stop here, as I am damm sleepy now. Will continue tomorrow in the next post.

IP Addressing/Subnetting : Chapter 1

Charter 1 : IP Address

1.0 Introduction

IP, Internet Protocol, address is a unique identifier for a host or host connection on an IP Network. IPv4 is a combination of a 32-bits numbers usually presented in a 4 decimal values. Each decimal value representing 8 bits from range 0 to 255 ( known as octet ) separated by decimal points.

EXAMPLE 1

IP Address : 192.168.0.1

This number is also view the values in binary form as below :  

Q : How to "translate" the 192.168.0.1 ( decimal IP ) value into binary format ?

Referring to the table shown below, we can "separate" the individual decimal value into :

• 192 = 128 + 64 which is 1100 0000
• 168 = 128 + 32 + 8 which is 1010 1000
• 0 = 0 which is 0000 0000
• 1 = 1 which is 0000 0001

Every IP address consists of two parts, one is identifying the node and the other one is identifying the network. The class of the address and the subnet mask determine which part belongs to the network address and which part belongs to the host address.

1.1 Address Classes for IPv4

For IPv4, there are 5 different address classes, in which you may identify it thru the first 4 bits of the first portion of decimal IP address.

• Class A addresses begin with 0xxx, or 1 to 126 decimal.
• Class B addresses begin with 10xx, or 128 to 191 decimal.
• Class C addresses begin with 110x, or 192 to 223 decimal.
• Class D addresses begin with 1110, or 224 to 239 decimal.
• Class E addresses begin with 1111, or 240 to 254 decimal.

Please also note that addresses beginning with 0111 1111, or 127 decimal, are reserved for loopback and internal testing for local machine ( a.k.a. 127.0.0.1 or also known as localhost ). Class D and class E are also not used as addresses as Class D addresses are reserved for multicasting and Class E is reserved for future use.

All the IP addresses from Class A, B and C are unique assignment in the public network. Anyhow, there are three IP network are reserved for private network :

1. 10.0.0.0, Subnet Mask 255.0.0.0 ( 10/8 prefix )
2. 172.16.0.0, Subnet Mask 255.240.0.0 ( 172.16/12 prefix )
3. 192.168.0.0, Subnet Mask 255.255.0.0 ( 192.168/16 prefix )

These group of private network can be used in the private internal address anywhere in the network, in which it will not be route-able in the Public Network as it will not be forwarded in router by default as define in RFC1918.

1.2 Subnet Masking

When you apply a subnet mask to an IP address, it would allows you to identify the network address and the host part of the addresses by using the bitwise logical AND operation between IP address and subnet mask. 

• The network bits are represented by 1s in the mask.
• The host bits are represented by 0s in the mask.

EXAMPLE 2

192.168.1.20 with subnet mask 255.255.255.0. 192.168.1 is representing the network while 20 is representing the host uniquely.

1100 0000. 1010 1000. 0000 0001. 0000 1100    =  192.168.1.20

1111 1111. 1111 1111. 1111 1111. 0000 0000    =  255.255.255.0

-----------------------------------------------------------------------------------------

1100 0000. 1010 1000. 0000 0001. 0000 0000    =  192.168.1.0

Therefore, 192.168.1.0 is the network address.

 

EXAMPLE 3

10.133.0.188 with subnet mask 255.255.224.0. 10.133.0 is representing the network while 0.188 is representing the host uniquely.

0000 1010. 1000 0101. 0000 0000. 1011 1100    =  10.133.0.188

1111 1111. 1111 1111. 1110 0000. 0000 0000    =  255.255.224.0

-----------------------------------------------------------------------------------------

0000 1010. 1000 0101. 0000 0000. 0000 0000    =  10.133.0.0

0000 1010. 1000 0101. 0001 1111. 1111 1111    =  10.133.31.255

Thus, the network address is 10.133.0.0.

In the case to get the broadcast address, you may change the subnet mask hosts bit to 1 and perform the bitwise logical AND operation between IP address and subnet mask. Thus, you may get the broadcast address of 10.133.31.255.

 

1.3 How logical AND works ?

The logical AND compares 2 digits, if both "1" then results "1", otherwise it is "0".

If you really still confusing on the logical AND, there is a simple trick to bypass the binary calculations but it is highly not advisable. :p

1. Open your calculator. ( Click START->Accessories->Calculator )
2. Select "Dec" ( decimal ).
3. Punch in "133" and followed by "AND" ( as shown in the picture )
4. Punch the netmask "133" and ENTER.
5. You will get the result "133" as per Example 3 above.

In the IP Addressing : Chapter 2, I will continue with more details' calculations to determine :

1. Number of hosts for a network based on subnet mask or host bit length.
2. How to "chop" a network based on subnet mask.