Wikipedia:Blocking IP addresses
From Wikipedia, the free encyclopedia
| This page outlines issues and problems related to blocking IP addresses. |
IP addresses can be blocked by administrators in the same way as registered users are. IP blocks can be more powerful and effective, but also have additional ramifications.
Contents |
[edit] General guidelines
[edit] Block lengths
Blocks should be based on the protection of Wikipedia rather than the punishment of offenders. Most IP addresses should not be blocked more than a few hours, since the malicious user will probably move on by the time the block expires. If there is persistent disruption or vandalism from an IP addresses, the block should be extended (with the 'anon-only' option selected) as long as is necessary to prevent further disruption.
However, IP addresses should almost never be indefinitely blocked. Many IPs are dynamically assigned and change frequently from one person to the next, and even static IP addresses are periodically re-assigned or have different users. In extreme cases, consider long-term blocks over a period of months or years instead. Long-term blocks should never be used for isolated incidents. Open proxies should generally be reported to the WikiProject on open proxies and blocked for two years.
If you do indefinitely block an IP address, please place {{indefblockedip}} or {{open proxy}} (do not substitute) on its user or user talk page for tracking purposes.
[edit] Shared IPs
Before implementing a long-term block on an IP address with a long history of vandalism, please check if it is shared by performing a WHOIS and Reverse DNS lookup query on the IP to determine if it belongs to a school or a proxy server. If a Shared IP's talk page is not already identified or tagged as such, use either the {{SharedIP}}, {{SharedIPEDU}}, or any one of the templates at Category:Shared IP header templates to do so. For anonymous-only blocks of Shared IPs, please consider using {{anonblock}} or {{schoolblock}} as your blocking reason.
[edit] Range blocks
Administrators can block ranges of IP addresses (commonly called rangeblocking). Use careful judgement and make them as brief as possible; this can affect over sixty-five thousand IP addresses, potentially affecting millions of users. These should be reserved as an absolute last resort.
For more information, see m:Range blocks. You need some knowledge of how networks and IP numbering work, and of binary arithmetic. If you don't, many other administrators do— ask on the Administrators' incidents noticeboard or on IRC. See Range blocks.
[edit] Problems and solutions
[edit] Autoblocks
An autoblock occurs when the software blocks usernames operating from a given IP address. This can occur indirectly when a registered user is blocked, autoblocking the IP. A single block can lead to hundreds of autoblocked legitimate users, so administrators should always be careful to watch for autoblocks in their name. For more information, see Wikipedia:Autoblock.
The simplest way to prevent autoblock problems is to check "Block anonymous users only" for IP addresses, or uncheck "Automatically block IP addresses used by this user" for registered users. Administrators should watch for autoblocks using the block log or pgk's autoblock toolserver script.
[edit] Shared and dynamic IP addresses
Many users operate from shared IP addresses, often those belonging to proxies used by large networks or Internet service providers. Since it is impossible to distinguish between individual users operating from shared IP addresses, blocking one may affect a very large number of legitimate users (ranging up to millions). Users operating from dynamic IP addresses change IP addresses periodically. This can compound the autoblock problem, particularly when they are also shared, because a block targetted at a malicious user may shift to a legitimate user while the target shifts to an unblocked IP address.
[edit] Open proxies
Open proxies are indefinitely blocked on sight according to the Foundation policy against open proxies. This may affect millions of users in rare cases; however, the IP should not be unblocked until it has been closed.
[edit] Particular cases
[edit] Public relations implications
Blocking certain IP addresses can have important public relations and political ramifications for the Wikimedia Foundation. If you must block any of the IP addresses below, you must notify the Wikimedia Foundation Communications Committee immediately so that they may be managed by the Foundation's press relations team. Avoid long blocks of these addresses and be especially careful in formulating your block messages because your block message will be seen and commented on by the press.
| Government IPs (political/public relations issues) | ||
|---|---|---|
| CIDR range | Range | Owner |
| — | 143.231.249.141 | United States House of Representatives |
| 156.33.0.0/16 | 156.33.*.* | United States Senate |
| 194.60.0.0/20 | 194.60.0.0 - 194.60.63.255 | UK Parliament |
