我升级到了 Ubuntu 18.04，突然命令行上连不上网，有线和无线都连不上，有些域名似乎无法解析，虽然ping 8.8.8.8能用，但service networking status输出错误。我在 askubuntu 上看到很多关于这个问题的调整，有ifconfig或/etc/network/interface但没有一个能完全起作用。sudo service network-manager restart也不起作用。
我的网络基本上一团糟。有没有办法将网络设置完全重置为正常工作的设置？既然这是一个热门话题，Ubuntu 怎么可能发布带有这种错误的主发行版？
编辑：
输出ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 00:8c:fa:8a:7c:ba txqueuelen 1000 (Ethernet)
RX packets 12829 bytes 5924414 (5.9 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 8755 bytes 1396496 (1.3 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 40521 bytes 4309970 (4.3 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 40521 bytes 4309970 (4.3 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.3 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::5e82:7f12:37f8:854f prefixlen 64 scopeid 0x20<link>
ether 34:de:1a:7f:93:1a txqueuelen 1000 (Ethernet)
RX packets 27441 bytes 22237443 (22.2 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 18332 bytes 5607005 (5.6 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
输出ip addr && cat /etc/resolv.conf && sudo lshw -C Network
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 00:8c:fa:8a:7c:ba brd ff:ff:ff:ff:ff:ff
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 34:de:1a:7f:93:1a brd ff:ff:ff:ff:ff:ff
inet 192.168.1.3/24 brd 192.168.1.255 scope global dynamic noprefixroute wlan0
valid_lft 84519sec preferred_lft 84519sec
inet6 fe80::5e82:7f12:37f8:854f/64 scope link noprefixroute
valid_lft forever preferred_lft forever
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.
nameserver 8.8.8.8
nameserver 127.0.0.53
options edns0
*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:07:00.0
logical name: eth0
version: 0c
serial: 00:8c:fa:8a:7c:ba
size: 1Gbit/s
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8168g-2_0.0.1 02/06/13 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s
resources: irq:16 ioport:3000(size=256) memory:c1700000-c1700fff memory:c1400000-c1403fff
*-network
description: Wireless interface
product: Wireless 3160
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:08:00.0
logical name: wlan0
version: cb
serial: 34:de:1a:7f:93:1a
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=4.15.0-45-generic firmware=17.948900127.0 ip=192.168.1.3 latency=0 link=yes multicast=yes wireless=IEEE 802.11
resources: irq:33 memory:c1600000-c1601fff
cat /etc/apt/sources.list：
# deb cdrom:[Ubuntu 15.10 _Wily Werewolf_ - Release amd64 (20151021)]/ wily main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
## Major bug fix updates produced after the final release of the
## distribution.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
deb http://archive.ubuntu.com/ubuntu bionic main universe restricted multiverse
## respective vendors as a service to Ubuntu users.
deb http://security.ubuntu.com/ubuntu/ bionic-security universe multiverse restricted main
deb http://archive.ubuntu.com/ubuntu bionic-updates universe multiverse restricted main
deb http://archive.ubuntu.com/ubuntu bionic-backports universe multiverse restricted main
deb http://archive.canonical.com/ubuntu bionic partner
# deb-src http://archive.canonical.com/ubuntu bionic partner
deb [arch=amd64,i386] https://deb.opera.com/opera-stable/ stable non-free
# deb-src [arch=amd64,i386] https://deb.opera.com/opera-stable/ stable non-free
答案1
Ubuntu 18.04 不再使用 ifupdown(/etc/network/interfaces)。这就是你出错的地方
他们改用了 netplan，非常麻烦。查看更多信息这里