R - 无法访问包安装的 url

Question

我最近在个人计算机(Windows 8)上安装了 R Studio(版本 0.99.892)，并尝试安装以下软件包:
ggplot2;
dplyr;
Markdown ；
蒂迪尔。

R 和 R Studio 都不能安装任何这些包。每次我尝试安装软件包时，都会收到我在这篇文章底部包含的一组警告。

我使用了 install.packages 命令以及内置的包安装工具。我尝试了几种不同的镜子。

我尝试过公立大学互联网资源、我自己的私有(private)互联网资源和电话线。我尝试通过 VPN 连接。我已将 R Studio 添加到我的 Windows 防火墙异常(exception)列表中，并且还完全禁用了 Windows 防火墙。我没有运行其他防火墙。

我在全局选项的“包”选项卡中切换了各种连接选项。

我可以在浏览器中访问 URL。

以下是来自 R Studio 的警告:

> install.packages("devtools")
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  unable to access index for repository https://cran.fhcrc.org/src/contrib:
  cannot open URL 'https://cran.fhcrc.org/src/contrib/PACKAGES'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be     resolved'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/src/contrib/PACKAGES'
Installing package into ‘C:/Users/Nikhailovich/Documents/R/win-library/3.2’
(as ‘lib’ is unspecified)
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  unable to access index for repository https://cran.fhcrc.org/src/contrib:
  cannot open URL 'https://cran.fhcrc.org/src/contrib/PACKAGES'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/src/contrib/PACKAGES'
Warning in install.packages :
  package ‘devtools’ is not available (for R version 3.2.3)
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  unable to access index for repository https://cran.fhcrc.org/bin/windows/contrib/3.2:
  cannot open URL 'https://cran.fhcrc.org/bin/windows/contrib/3.2/PACKAGES'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.2:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.2/PACKAGES'

以下是来自 R (3.2.3) 的警告:

> install.packages("ggplot2")
Installing package into ‘C:/Users/Nikhailovich/Documents/R/win-library/3.2’
(as ‘lib’ is unspecified)
--- Please select a CRAN mirror for use in this session ---
Error in download.file(url, destfile = f, quiet = TRUE) : 
  cannot open URL 'https://cran.r-project.org/CRAN_mirrors.csv'
In addition: Warning message:
In download.file(url, destfile = f, quiet = TRUE) :
  InternetOpenUrl failed: 'The server name or address could not be resolved'
Warning: unable to access index for repository https://dirichlet.mat.puc.cl/src/contrib:
  cannot open URL 'https://dirichlet.mat.puc.cl/src/contrib/PACKAGES'
Warning: unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/src/contrib/PACKAGES'
Warning: unable to access index for repository https://dirichlet.mat.puc.cl/bin/windows/contrib/3.2:
  cannot open URL 'https://dirichlet.mat.puc.cl/bin/windows/contrib/3.2/PACKAGES'
Warning: unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.2:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.2/PACKAGES'
Warning message:
package ‘ggplot2’ is not available (for R version 3.2.3) 

在 R 和 R Studio 中有几个关于包安装的 stackexchange 帖子，但我找不到任何可以回答我的特殊情况的帖子。提前感谢任何知道发生了什么的人

Answer 1

我想补充一点，我遇到了这个问题，但修复不是在 R 中，而是在我们的系统中。我们的 IT 人员说:由于某种未知原因，DNS 解析器服务无法解析主机名。我已经重新启动了 resolvd 服务。服务器现在可以解析主机名。
他的错误是:名称解析暂时失败