localhost 和 0.0.0.0 的 IPV6 是什么? [英] What is IPV6 for localhost and 0.0.0.0?

问题描述

众所周知，localhost 的 IPv4 地址是 127.0.0.1(环​​回地址).localhost 和 0.0.0.0 的 IPv6 地址是什么，因为我需要阻止一些广告主机.

As we all know the IPv4 address for localhost is 127.0.0.1 (loopback address). What is the IPv6 address for localhost and for 0.0.0.0 as I need to block some ad hosts.

推荐答案

众所周知，localhost 的 IPv4 地址是 127.0.0.1(环​​回地址).

As we all know that IPv4 address for localhost is 127.0.0.1 (loopback address).

实际上，127.0.0.0/8 中的任何 IPv4 地址都是环回地址.

Actually, any IPv4 address in 127.0.0.0/8 is a loopback address.

在 IPv6 中，环回范围的直接模拟是 ::1/128.所以 ::1(长格式 0:0:0:0:0:0:0:1)是唯一的 IPv6 环回地址.

In IPv6, the direct analog of the loopback range is ::1/128. So ::1 (long form 0:0:0:0:0:0:0:1) is the one and only IPv6 loopback address.

^{虽然主机名 localhost 通常会解析为 127.0.0.1 或 ::1，但我看到有人遇到过这样的情况将其绑定到不是环回地址的 IP 地址.这有点疯狂......但有时人们会这样做.}

^{While the hostname localhost will normally resolve to 127.0.0.1 or ::1, I have seen cases where someone has bound it to an IP address that is not a loopback address. This is a bit crazy ... but sometimes people do it.}

^{我说这太疯狂了"，因为这样做可能会破坏应用程序的假设；例如应用程序可能会尝试对环回 IP 进行反向查找，但无法获得预期结果.在最坏的情况下，应用程序最终可能会意外地通过不安全的网络发送敏感流量……尽管您可能还需要犯其他错误才能实现"这一目标.}

阻止 0.0.0.0 没有意义.在 IPv4 中，它永远不会被路由.IPv6 中的等价物是 :: 地址(长格式 0:0:0:0:0:0:0:0)......它也从不路由.

Blocking 0.0.0.0 makes no sense. In IPv4 it is never routed. The equivalent in IPv6 is the :: address (long form 0:0:0:0:0:0:0:0) ... which is also never routed.

0.0.0.0 和 :: 地址保留表示任何地址".因此，例如，提供 Web 服务的程序可能绑定到 0.0.0.0 端口 80 以通过任何主机的 IPv4 地址接受 HTTP 连接.这些地址不能作为 IP 数据包的源地址或目标地址.

The 0.0.0.0 and :: addresses are reserved to mean "any address". So, for example a program that is providing a web service may bind to 0.0.0.0 port 80 to accept HTTP connections via any of the host's IPv4 addresses. These addresses are not valid as a source or destination address for an IP packet.

最后，一些评论询问了 ::/128 与 ::/0 与 ::.

Finally, some comments were asking about ::/128 versus ::/0 versus ::.

这有什么区别?

严格来说，前两个是 CIDR 表示法，而不是 IPv6 地址.他们实际上是在指定一个范围的IP地址.CIDR 由一个 IP 地址和一个附加数字组成，该数字指定网络掩码中的位数.两者一起指定了地址范围；即通过忽略从给定地址中屏蔽的位形成的地址集.

Strictly speaking, the first two are CIDR notation not IPv6 addresses. They are actually specifying a range of IP addresses. A CIDR consists of a IP address and an additional number that specifies the number of bits in a netmask. The two together specify a range of addresses; i.e. the set of addresses formed by ignoring the bits masked out of the given address.

所以:

• :: 仅表示 IPv6 地址 0:0:0:0:0:0:0:0
• ::/128 表示 0:0:0:0:0:0:0:0，网络掩码由 128 位组成.这给出了一个网络范围，其中只有一个地址.
• ::/0 表示 0:0:0:0:0:0:0:0，网络掩码由 0 位组成.这给出了一个包含 2¹²⁸ 个地址的网络范围.即它是整个 IPv6 地址空间！

• :: means just the IPv6 address 0:0:0:0:0:0:0:0
• ::/128 means 0:0:0:0:0:0:0:0 with a netmask consisting of 128 bits. This gives a network range with exactly one address in it.
• ::/0 means 0:0:0:0:0:0:0:0 with a netmask consisting of 0 bits. This gives a network range with 2¹²⁸ addresses in it.; i.e. it is the entire IPv6 address space!

有关更多信息，请阅读有关 IPv4 和IPv6 地址和 CIDR 表示法:

For more information, read the Wikipedia pages on IPv4 & IPv6 addresses, and CIDR notation:

• https://en.wikipedia.org/wiki/IPv4_address
• https://en.wikipedia.org/wiki/IPv6_address
• https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing

这篇关于localhost 和 0.0.0.0 的 IPV6 是什么?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！