一、問題的出現
git
用VirtualBox安裝Win10,網絡鏈接選擇"橋接網卡",無任何問題;shell
用VirtualBox安裝(第一個CentOS,s1)CentOS-7-x86_64-Minimal-1511.iso,網絡鏈接選擇"橋接網卡",無任何問題,可以正常上網,yum,ping都正常;網絡
用VirtualBox安裝(第二個CentOS,s2)CentOS-7-x86_64-Minimal-1511.iso,網絡鏈接選擇"橋接網卡",問題就來了,運行yum -y install git,一直報錯"loaded plugins fastestmirror you need to be root to perform this command",此時還未意識到是網絡問題致使的,各類折騰,一開始方向就錯了,一直從"yum install"的錯誤查找解決方法,各類修改、重啓都沒解決問題。後來實在無法,嘗試了一下ping 172.16.70.170(內網ip),竟然提示"connect: Network is unreachable" ,果斷查看當前網絡信息"ip addr",沒有獲取到網絡地址,這才發現竟然是網絡問題致使"yum install 錯誤:loaded plugins fastestmirror you need to be root to perform this command"。less
二、 解決問題oop
通過一番折騰,終於找到了問題,接下來就是如何解決,按照通常的思路是去"/etc/sysconfig/network-scripts"查看ifcfg-eth0內容,問題又來了,竟然沒有這個文件,當時就迷茫了,不知道怎麼辦了。post
$ cd /etc/sysconfig/network-scripts/ $ ls ifcfg-enp0s3 ifdown-post ifup-eth ifup-routes ifcfg-lo ifdown-ppp ifup-ippp ifup-sit ifdown ifdown-routes ifup-ipv6 ifup-tunnel ifdown-bnep ifdown-sit ifup-isdn ifup-wireless ifdown-eth ifdown-tunnel ifup-plip init.ipv6-global ifdown-ippp ifup ifup-plusb network-functions ifdown-ipv6 ifup-aliases ifup-post network-functions-ipv6 ifdown-isdn ifup-bnep ifup-ppp
各類查找"ifcfg-eth0 missing",也沒解決問題。忽然想起我不是有一個可以上網的s1麼,而後登陸s1,一樣進入"/etc/sysconfig/network-scripts/"目錄查看文件列表,竟然和s3一摸同樣,這就奇怪了,同樣的文件,問什麼不能一個能上網一個不能上網呢?而後運行"ip addr"查看網絡this
$ ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 08:00:27:8a:4b:83 brd ff:ff:ff:ff:ff:ff inet 172.16.70.173/24 brd 172.16.70.255 scope global dynamic enp0s3 valid_lft 256686sec preferred_lft 256686sec inet6 fe80::a00:27ff:fe8a:4b83/64 scope link valid_lft forever preferred_lft forever
從信息裏面能夠看出網絡指向的配置是enp0s3,而不是eth0,而後對比一下s1與s2的ifcfg-enp0s3文件,只有下面一行不同spa
s1
code
ONBOOT=yes
s2
orm
ONBOOT=no
而後修改s2的/etc/sysconfig/network-scripts/ifcfg-enp0s3文件內容與s1保持一致,而後重啓,再次ping 172.16.70.170,通了,問題解決了,運行 yun install 也不提示"loaded plugins fastestmirror you need to be root to perform this command"錯誤了。
$ vi /etc/sysconfig/network-scripts/ifcfg-enp0s3 $ reboot $ ping 172.16.70.170 PING 172.16.70.170 (172.16.70.170) 56(84) bytes of data. 64 bytes from 172.16.70.170: icmp_seq=1 ttl=64 time=0.554 ms 64 bytes from 172.16.70.170: icmp_seq=2 ttl=64 time=0.245 ms 64 bytes from 172.16.70.170: icmp_seq=3 ttl=64 time=0.306 ms ^C --- 172.16.70.170 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2001ms rtt min/avg/max/mdev = 0.245/0.368/0.554/0.134 ms $ yum -y install git
三、總結
在虛擬機上安裝CentOS的默認網絡名稱不必定都是eth0,有可能網絡設置不同,而默認網絡名稱也不同;
在解決問題的時候方向很重要,若是走錯了,那就愈來愈遠;
經驗很重要,若是以前碰到個相似問題,就不會花這麼多時間在解決這種基本配置的小問題上;