每小时有一两次，我的 Ubuntu 机器的以太网连接会断开：
$ ping google.com
(nothing happens)
10-20 秒后（尽管有时更长）它会神奇地回来。
在中断期间，我无法 ping google.com 或 IP，因此我认为这不是 DNS 问题。我尝试了多种方法来调试：
- 重新启动
- 更新/升级了所有软件包。
- 已卸载并重新安装
network-manager。 - 交换以太网电缆。
我的同事与我连接到同一个路由器，他们没有遇到这个问题，所以这似乎是我的计算机上的问题。
有什么想法吗？我刚刚用完了这些，这真是令人沮丧！
以下是有关我的系统的大量信息：
$ lspci
00:00.0 Host bridge: Intel Corporation Device 591f (rev 05)
00:02.0 VGA compatible controller: Intel Corporation Device 5912 (rev 04)
00:14.0 USB controller: Intel Corporation 200 Series PCH USB 3.0 xHCI Controller
00:14.2 Signal processing controller: Intel Corporation 200 Series PCH Thermal Subsystem
00:16.0 Communication controller: Intel Corporation 200 Series PCH CSME HECI #1
00:17.0 SATA controller: Intel Corporation 200 Series PCH SATA controller [AHCI mode]
00:1f.0 ISA bridge: Intel Corporation 200 Series PCH LPC Controller (H270)
00:1f.2 Memory controller: Intel Corporation 200 Series PCH PMC
00:1f.3 Audio device: Intel Corporation 200 Series PCH HD Audio
00:1f.4 SMBus: Intel Corporation 200 Series PCH SMBus Controller
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (2) I219-V
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 17.04
Release: 17.04
Codename: zesty
$ ifconfig
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 0.0.0.0
inet6 fe80::42:e7ff:fe8d:d514 prefixlen 64 scopeid 0x20<link>
ether 02:42:e7:8d:d5:14 txqueuelen 0 (Ethernet)
RX packets 25739 bytes 1591975 (1.5 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 116624 bytes 169185651 (169.1 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s31f6: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.201.32.57 netmask 255.255.255.0 broadcast 10.201.32.255
inet6 fe80::7285:c2ff:fe2a:efa8 prefixlen 64 scopeid 0x20<link>
ether 70:85:c2:2a:ef:a8 txqueuelen 1000 (Ethernet)
RX packets 1938458 bytes 1438227394 (1.4 GB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1442649 bytes 772299655 (772.2 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 16 memory 0xdf000000-df020000
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 181354 bytes 50978753 (50.9 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 181354 bytes 50978753 (50.9 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
$ ethtool enp0s31f6
Settings for enp0s31f6:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
MDI-X: on (auto)
Cannot get wake-on-lan settings: Operation not permitted
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes
以下是我在/var/log/syslog连接断开时看到的情况：
Jul 7 12:44:02 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:03 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.
Jul 7 12:44:04 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:04 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.
Jul 7 12:44:05 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:06 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.
Jul 7 12:44:07 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:09 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.
Jul 7 12:44:11 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:11 dv systemd-resolved[1259]: Using degraded feature set (UDP+EDNS0+DO) for DNS server 10.201.1.18.
Jul 7 12:44:13 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.
Jul 7 12:44:15 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:17 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.
Jul 7 12:44:18 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:18 dv systemd-resolved[1259]: Using degraded feature set (UDP) for DNS server 10.201.1.18.
Jul 7 12:44:18 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.
Jul 7 12:44:20 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.18 for interface enp0s31f6.
Jul 7 12:44:22 dv systemd-resolved[1259]: Switching to DNS server 10.201.1.15 for interface enp0s31f6.