도움말:대역 차단

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This page is a translated version of the page Help:Range blocks and the translation is 14% complete.

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PD 참고: 이 문서를 편집하면, CC0에 따라 당신의 기여를 배포하는 데 동의한 것으로 간주됩니다. 자세한 내용은 퍼블릭 도메인 도움말 문서를 보십시오.
PD
IPv6 대역 차단에 대해서는 /IPv6을 참조하시기 바랍니다.

대역 차단Special:Block 문서를 통해 특정 IP 주소 묶음, 즉 IP 대역에 대해 해당 위키에서의 편집, 계정 만들기, 이메일 보내기 등의 활동을 할 수 없도록 하는 기술적인 제한입니다. 만일 차단을 수행한 관리자가 차단 시 "이 IP를 이용하는 로그인한 사용자가 편집하는 것을 막기" 박스에 체크했다면, 등록된 계정에 로그인하고 있더라도 차단된 IP 대역을 사용하고 있다면 제한의 영향을 받습니다.

대역 차단은 모든 위키미디어 위키에서 사용하고 있습니다. 만약 여러분의 위키에서 대역 차단을 할 수 없다면 LocalSettings.phpManual:LocalSettings.php$wgSysopRangeBansManual:$wgSysopRangeBans = true; 코드를 추가하십시오. (미디어위키 1.18.0 버전 이상에서는 영구적으로 가능합니다.)

To block an IP range from Special:Block, enter the first IP address in the range followed by a forward slash and a Classless inter-domain routing (CIDR) suffix. 대역 차단에 대해 충분히 이해하고 있지 않다면 대역 차단을 피해야 합니다. 그렇지 않으면 10,000에서 수 백만의 문제 없는 사용자가 차단을 당할 수도 있습니다.

이 문서는 주로 IPv4에 대해서 설명하고 있습니다. IPv6 차단과 유사하게 작동하나, 다른 의미를 갖고 있습니다. /IPv6를 참고하세요

기술적이지 않은 설명

IP 주소는 여러 숫자 블럭들로 나뉘어 집니다. IP 대역 148.20.57.0부터 148.20.57.255까지가 있다고 합시다. 255까지 있다고 하면 다음 주소는 148.20.58.0이 될 겁니다.

IP 주소는 더 작거나 큰 블록들로 나뉘어 질 수 있습니다. 사용가능한 가장 작은 블록은 4입니다. This could be one of the following:

148.20.57.0 - 148.20.57.3,
148.20.57.4 - 148.20.57.7,
148.20.57.8 - 148.20.57.11, ...

Of each block of 4 numbers, only two can be assigned to a computer. The first and last numbers of any block are reserved for network communication. These are level 30 blocks and can be expressed like this:

148.20.57.0/30,
148.20.57.4/30,
148.20.57.8/30, ...

The next largest block is 8. They can be as follows:

148.20.57.0 - 148.20.57.7,
148.20.57.8 - 148.20.57.15,
148.20.57.16 - 148.20.57.23, ...

In this block of 8 numbers only 6 can be assigned to a computer as, once again, the first and last numbers in a block are reserved for specific uses in network communication. These can also be expressed as follows:

148.20.57.0/29,
148.20.57.8/29,
148.20.57.16/29, ...

From this point on, the number of IP addresses in a block continues to double: 16, 32, 64, 128, 256, etc.

A block of 16 would start 148.20.57.0/28.
A block of 32 would start 148.20.57.0/27.
A block of 64 would start 148.20.57.0/26.
A block of 128 would start 148.20.57.0/25.
A block of 256 would start 148.20.57.0/24.

So if you have an IP address and you want to block the range assigned how do you know which one to use? Let's say you have a problem with 148.20.57.34. You can lookup who has this IP address at http://arin.net/whois/?queryinput=148.20.57.34. Say this tells us that this IP address is assigned, along with a LOT of others in a /17 range, to the Department of Defense. We certainly don't want to block a large block of the DoD! The rule of thumb is block as little as possible. Only block a range if there is a cluster of IP addresses giving a problem.

There's a calculator that is very useful for this:

http://www.csgnetwork.com/ipinfocalc.html

Go to this site and enter 148.20.57.34 into the first set of blanks. Now select Network Prefix Length and enter 27 (this will give a block of 32 addresses) and click Calculate Network Information. This will show us a block of 32 IP addresses that include 148.20.57.34. (The first - network - and the last - broadcast - addresses will be displayed along with the usable addresses in the range.) You can use this tool to test ranges to be sure they are what you want before entering the information to initiate the block.

Technical explanation

CIDR notation is written as the IP address, a slash, and the CIDR suffix (for example, the IPv4 "10.2.3.41/24" or IPv6 "a3:bc00::/24"). The CIDR suffix is the number of starting digits every IP address in the range have in common when written in binary.

For example: "10.10.1.32" is binary "00001010.00001010.00000001.00100000", so 10.10.1.32/27 will match the first 27 digits ("00001010.00001010.00000001.00100000"). The IP addresses 10.10.1.3210.10.1.63, when converted to binary, all have the same 27 first digits and will be blocked if 10.10.1.32/27 is blocked.

As the CIDR suffix increases, the block affects fewer IP addresses (see table of sample ranges). CIDR suffixes are not the same for IPv4 addresses as they are for IPv6 addresses; the same CIDR suffix in IPv4 blocks =79,228,162,514,264,337,593,543,950,336 times as many addresses in IPv6.

Calculating the CIDR suffix

You can use the table of sample ranges below to guess the range, use a computer script, or manually calculate the range.

Conversion to binary

The first step in manually calculating a range is to convert the first and last IP address to binary representation. (This assumes you're not using a computer script, which can probably calculate the range for you anyway.) An IP address is composed of four groups of eight ones and zeros. Each group represents a number from 0 to 255. To convert a number to binary, you can use a reference table or know the value of each binary digit:

Binary digit:   1   1   1   1   1   1   1   1
Value: 128  64  32  16   8   4   2   1

Proceeding from left to right, fill in 1 if the number is at least that value, and subtract that value (if it's not, fill in 0 and don't subtract). For example, to calculate 240:

  1. 240 is at least 128, so place 1 and subtract 128.
  2. 112 (240-128) is at least 64, so place 1 and subtract 64.
  3. 48 (112-64) is at least 32, so place 1 and subtract 32.
  4. 16 (48-32) is at least 16, so place 1 and subtract 16.
  5. Since the remaining value is zero, all the remaining places are 0.

Thus, 240 is 1111 0000 because it can be represented as 128+64+32+16+0+0+0+0.

Calculate range

  1. Place both IP addresses one atop the other, and count how many starting digits are exactly alike. This is the CIDR suffix.
  2. Double-check! Being off by one digit could extend your block by thousands of addresses.

The example below calculates the CIDR range between 69.208.0.0 and 69.208.0.255. Note that this is a simple example; some groups of IP addresses do not so neatly fit CIDR suffixes, and need multiple different-sized blocks to block the exact range.

IP addresses:
  69.208.0.0
  69.208.0.255
Convert to binary:
  0100 0101.1101 0000.0000 0000.0000 0000
  0100 0101.1101 0000.0000 0000.1111 1111
Count identical first numbers:
  0100 0101.1101 0000.0000 0000.0000 0000
  0100 0101.1101 0000.0000 0000.1111 1111
  |____________________________|
            24 digits
CIDR range:
  69.208.0.0/24

Table of sample ranges

The table below shows the IPv4 blocks each CIDR suffix affects. Note that MediaWiki only supports blocking CIDR suffixes 16 - 32 in IPv4 and 19 (formerly 64) - 128 in IPv6 by default (subject to $wgBlockCIDRLimitManual:$wgBlockCIDRLimit). See /IPv6 for an IPv6 range table.

CIDR Start Range End Range Total addresses Bits selected in IP address
69.208.0.0/0 0.0.0.0 255.255.255.255 4,294,967,296 ********.********.********.********
69.208.0.0/1 0.0.0.0 127.255.255.255 2,147,483,648 0*******.********.********.********
69.208.0.0/4 64.0.0.0 79.255.255.255 268,435,456 0100****.********.********.********
69.208.0.0/8 69.0.0.0 69.255.255.255 16,777,216 01000101.********.********.********
69.208.0.0/11 69.192.0.0 69.223.255.255 2,097,152 01000101.110*****.********.********
69.208.0.0/12 69.208.0.0 69.223.255.255 1,048,576 01000101.1101****.********.********
69.208.0.0/13 69.208.0.0 69.215.255.255 524,288 01000101.11010***.********.********
69.208.0.0/14 69.208.0.0 69.211.255.255 262,144 01000101.110100**.********.********
69.208.0.0/15 69.208.0.0 69.209.255.255 131,072 01000101.1101000*.********.********
69.208.0.0/16 69.208.0.0 69.208.255.255 65,536 01000101.11010000.********.********
69.208.0.0/17 69.208.0.0 69.208.127.255 32,768 01000101.11010000.0*******.********
69.208.0.0/18 69.208.0.0 69.208.63.255 16,384 01000101.11010000.00******.********
69.208.0.0/19 69.208.0.0 69.208.31.255 8,192 01000101.11010000.000*****.********
69.208.0.0/20 69.208.0.0 69.208.15.255 4,096 01000101.11010000.0000****.********
69.208.0.0/21 69.208.0.0 69.208.7.255 2,048 01000101.11010000.00000***.********
69.208.0.0/22 69.208.0.0 69.208.3.255 1,024 01000101.11010000.000000**.********
69.208.0.0/23 69.208.0.0 69.208.1.255 512 01000101.11010000.0000000*.********
69.208.0.0/24 69.208.0.0 69.208.0.255 256 01000101.11010000.00000000.********
69.208.0.0/25 69.208.0.0 69.208.0.127 128 01000101.11010000.00000000.0*******
69.208.0.0/26 69.208.0.0 69.208.0.63 64 01000101.11010000.00000000.00******
69.208.0.0/27 69.208.0.0 69.208.0.31 32 01000101.11010000.00000000.000*****
69.208.0.0/28 69.208.0.0 69.208.0.15 16 01000101.11010000.00000000.0000****
69.208.0.0/29 69.208.0.0 69.208.0.7 8 01000101.11010000.00000000.00000***
69.208.0.0/30 69.208.0.0 69.208.0.3 4 01000101.11010000.00000000.000000**
69.208.0.0/31 69.208.0.0 69.208.0.1 2 01000101.11010000.00000000.0000000*
69.208.0.0/32 69.208.0.0 69.208.0.0 1 01000101.11010000.00000000.00000000


Default limitation

The default MediaWiki installation limits range blocks to no larger than /16 IPv4 rangeblocks (65,536 addresses). To block larger ranges $wgBlockCIDRLimitManual:$wgBlockCIDRLimit needs to be set accordingly in LocalSettings.phpManual:LocalSettings.php.

References

External links