Ubuntu 18.04 DNS配置解决域名无法访问或者访问很慢的问题
之前在公司自己弄了个OP的路由器,之前一直都跑的好好的(经常在公司内网和自己的OP之间切换),但是这周发现内网网口的时候上网无问题,但是用自己OP的时候无法访问外网,ping的通IP,但是域名无法解析,网站也无法打开,确定是DNS配置出了问题,花了点时间查了下资料,修复了此问题,省的重新装机了,下面记录下踩到的坑,以及解决的方法.
踩到的坑
其实整体思路就是配置好DNS服务器就可以了,找到相关配置文件修改下其实就行,但是下面这几种方式,我试过了,不行.
修改/etc/resolv.conf配置，但是一旦重启，就恢复默认值了。有个博主推荐安装下resolvconf,然后修改/etc/resolvconf/resolv.conf.d/ 目录下head文件(head就是在/etc/resolv.conf头部添加配置,tail就是在尾部)
sudo apt install resolvconf
sudo vim /etc/resolvconf/resolv.conf.d/head
在head中添加一行,
nameserver 114.114.114.114
注意,一定要在最后回车换行.重启后,可以看到/etc/resolv.conf里面配置变成了
nameserver 114.114.114.114
nameserver 127.0.0.53
其实可以关闭本地DNS的,如下操作即可,
sudo systemctl disable systemd-resolved.service
sudo systemctl stop systemd-resolved
重启后,发现/etc/resolv.conf里面只剩下114的DNS配置了.
但是这个方式并没有解决我切换到自己的OP时无法联网的问题,并且这么操作后,公司内网也打不开了,这种方式失败.
另一种方式,其实这这个类似,修改/etc/systemd/resolved.conf配置文件,修改成
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See resolved.conf(5) for details
[Resolve]
DNS=8.8.8.8
FallbackDNS=1.1.1.1
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#Cache=yes
#DNSStubListener=yes
如此修改后,/etc/resolv.conf重启后会默认设置DNS服务器为DNS=8.8.8.8,思路是和第一种方式一致的,但是还是没用.
还有修改/etc/NetworkManager下面的配置文件的,但是依然没用.
解决方法
修改/etc/netplan/01-network-manager-all.yaml配置文件,具体操作方法如下:
先看下电脑的网卡配置信息,
ifconfig
拿我的电脑举栗子,显示如下,
docker0: flags=4099 mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:5a:e8:db:2b txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
eno1: flags=4163 mtu 1500
inet 172.16.15.69 netmask 255.255.255.0 broadcast 172.16.15.255
inet6 fe80::7f3e:10c5:5cbb:fdee prefixlen 64 scopeid 0x20
ether 1c:a0:b8:77:a1:3c txqueuelen 1000 (Ethernet)
RX packets 35475 bytes 15108483 (15.1 MB)
RX errors 0 dropped 16447 overruns 0 frame 0
TX packets 7396 bytes 1520156 (1.5 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 23 memory 0xa3300000-a3320000
lo: flags=73 mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 9045 bytes 8238003 (8.2 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 9045 bytes 8238003 (8.2 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlx502b73c9007e: flags=4163 mtu 1500
inet 192.168.8.129 netmask 255.255.255.0 broadcast 192.168.8.255
inet6 fe80::3c12:8ccf:3ad7:3978 prefixlen 64 scopeid 0x20
ether 50:2b:73:c9:00:7e txqueuelen 1000 (Ethernet)
RX packets 14476 bytes 14118753 (14.1 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 11756 bytes 2047466 (2.0 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
从中可以看出,我这边是两个网卡的,一个是eno1(本地有线连接),另一个是wlx502b73c9007e(自己加的无线网卡),记下来这两个网卡的名称和IP,下面用得上.
然后开始配置/etc/netplan/01-network-manager-all.yaml
sudo gedit /etc/netplan/01-network-manager-all.yaml
修改后,显示为
# Let NetworkManager manage all devices on this system
network:
version: 2
renderer: NetworkManager
#renderer: networkd
ethernets:
wlx502b73c9007e :
addresses: [192.168.8.129/24]
dhcp4: yes
optional: true
gateway4: 192.168.8.1
nameservers:
addresses: [8.8.8.8,8.8.4.4,114.114.114.114]
然后执行下面命令：
sudo netplan apply
sudo systemctl start systemd-networkd.service
应用所做修改就可以了．
我这里只修改了,我自己添加的网卡配置,eno1网卡按照默认的配置运行,当然大家也可以按照自己的需求去修改DNS的服务器,我这里用的就是Google和114,大部分场景我这边都可以覆盖了.
好的,打完收工,最后查了下,好像从18.04开始,都是使用netplan配置网卡了,所以之前的方式通通失效.