# 出现情景
Mac升级到新版本使用brew upgrade
出现.
Error:
homebrew-core is a shallow clone.
To `brew update`, first run:
git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow
This restriction has been made on GitHub's request because updating shallow
clones is an extremely expensive operation due to the tree layout and traffic of
Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
automatically to avoid repeatedly performing an expensive unshallow operation in
CI systems (which should instead be fixed to not use shallow clones). Sorry for
the inconvenience!
1
2
3
4
5
6
7
8
9
10
2
3
4
5
6
7
8
9
10
# 简介
IP 地址(英语:Internet Protocol Address)是一种在Internet上的给主机编址的方式,也称为网际协议地址。常见的IP地址,分为IPv4与IPv6两大类。
Internet 上的每台主机都有一个唯一的IP地址。IP协议就是使用这个地址在主机之间传递信息,这是Internet 能够运行的基础。IPv4 地址的长度为32位,分为4段,每段8位,用十进制数字表示,每段数字范围为0~255,段与段之间用句点隔开。例如 49.232.22.14。目前IP技术可能使用的IP地址最多可有约42亿个(232)。有关 IPv4 的更多信息,可参考IPv4
随着网络的飞速发展,IP资源越来越紧缺,所以科研组织开始研究 IPv6。从IPv4到IPv6最显著的变化就是网络地址的长度。最大可达 2128, 约为 3.403 x 1038。有关 IPv6 的更多信息,可参考可参考IPv6