我在 ubuntu server 18.04 中遇到了网桥问题。这台机器有两个网卡，我将网桥绑定到其中一个，并将容器连接到网桥。我正在为容器上的局域网设置服务，并通过网桥使用静态 IP 使它们可用于子网。但是，当我启动系统时，我最终没有在网桥上获得 IP 地址：
br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::7e8b:caff:fe03:57b0 prefixlen 64 scopeid 0x20<link>
ether 7c:8b:ca:03:57:b0 txqueuelen 1000 (Ethernet)
RX packets 167 bytes 19385 (19.3 KB)
RX errors 0 dropped 50 overruns 0 frame 0
TX packets 36 bytes 2946 (2.9 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::7e8b:caff:fe03:57b0 prefixlen 64 scopeid 0x20<link>
ether 7c:8b:ca:03:57:b0 txqueuelen 1000 (Ethernet)
RX packets 758 bytes 637232 (637.2 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 433 bytes 33998 (33.9 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp3s0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 30:9c:23:41:a4:1b txqueuelen 1000 (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
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 64 bytes 5104 (5.1 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 64 bytes 5104 (5.1 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethCHVFR2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::fcf7:29ff:fe05:734b prefixlen 64 scopeid 0x20<link>
ether fe:f7:29:05:73:4b txqueuelen 1000 (Ethernet)
RX packets 348 bytes 26797 (26.7 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 422 bytes 350547 (350.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethLPOSTU: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::fcb3:33ff:fe5b:4bbb prefixlen 64 scopeid 0x20<link>
ether fe:b3:33:5b:4b:bb txqueuelen 1000 (Ethernet)
RX packets 49 bytes 4363 (4.3 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 172 bytes 279551 (279.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
这是全局主机上的 /etc/network/interfaces 文件：
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto enp2s0
iface enp2s0 inet manual
auto enp3s0
iface enp3s0 inet manual
# address 192.168.5.19
# netmask 255.255.255.0
# gateway 192.168.5.1
# dns-nameserver 8.8.8.8
#
auto br0
iface br0 inet static
bridge_ports enp2s0
address 192.168.5.20
# network 192.168.5.0
netmask 255.255.255.0
broadcast 192.168.5.255
gateway 192.168.5.1
# bridge_fd 9
# bridge_hello 2
# bridge_maxage 12
bridge_stp off
dns-nameserver 8.8.8.8
dns-search XXX.network
问题是，当我发出“服务网络重启”时，所有内容都按照预期的方式组合在一起：
br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.5.20 netmask 255.255.255.0 broadcast 192.168.5.255
inet6 fe80::7e8b:caff:fe03:57b0 prefixlen 64 scopeid 0x20<link>
ether 7c:8b:ca:03:57:b0 txqueuelen 1000 (Ethernet)
RX packets 122 bytes 12409 (12.4 KB)
RX errors 0 dropped 21 overruns 0 frame 0
TX packets 91 bytes 8072 (8.0 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 7c:8b:ca:03:57:b0 txqueuelen 1000 (Ethernet)
RX packets 914 bytes 654161 (654.1 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 522 bytes 41870 (41.8 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp3s0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 30:9c:23:41:a4:1b txqueuelen 1000 (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
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 64 bytes 5104 (5.1 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 64 bytes 5104 (5.1 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethCHVFR2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::fcf7:29ff:fe05:734b prefixlen 64 scopeid 0x20<link>
ether fe:f7:29:05:73:4b txqueuelen 1000 (Ethernet)
RX packets 350 bytes 26933 (26.9 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 430 bytes 351218 (351.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethLPOSTU: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::fcb3:33ff:fe5b:4bbb prefixlen 64 scopeid 0x20<link>
ether fe:b3:33:5b:4b:bb txqueuelen 1000 (Ethernet)
RX packets 54 bytes 4625 (4.6 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 180 bytes 280218 (280.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
一切都开始正常工作。有什么想法我应该查看哪里才能让网络正常启动，而不是需要重新配置才能进行配置？
谢谢！
答案1
原来是 ifupdown 和 netplan 之间的交互。配置 netplan 后，系统正常运行。我怀疑问题是启动过程中的定时问题，由于网络子系统的关键部分尚未启动，因此无法为网桥分配地址。我清除了 ifupdown 并配置了 netplan，一切开始正常工作。
感谢@chili555 为我指明正确的方向。