我当前的问题触及了我的基本网络技能的极限。
简而言之：我通过连接路由器和媒体中心的网线“接入”了一台具有多个网络接口的服务器。我尝试以透明的方式实现这一点。
网络拓扑结构为：
Other machine (192.168.0.2) -- Router (192.168.0.1) -- Media center (192.168.0.3)
现在是：
Other machine (192.168.0.2) -- Router (192.168.0.1) -- New server (192.168.0.4) -- Media center (192.168.0.3)
我在服务器上建立了桥接连接，就像在 netplan 上一样：
network:
version: 2
ethernets:
eno1:
dhcp4: no
eno2:
dhcp4: no
bridges:
br0:
interfaces: [eno1, eno2]
addresses: [192.168.0.4/24]
gateway4: 192.168.0.1
nameservers:
search: []
addresses: [192.168.0.2]
新服务器（192.168.0.4）可以 ping 和 ssh 到媒体中心（192.168.0.3）和路由器或网络的其余部分（例如 192.168.0.2）。
媒体中心 (192.168.0.3) 可以 ping 和 ssh 新服务器 (192.168.0.4)，但不能 ping 和 ssh 路由器或网络的其余部分。相反，路由器和网络的其余部分无法与媒体中心 (192.168.0.3) 通信。
我可以通过定义来实现我想要做的事情吗netplan 配置中的路由（但我在这里有点不够深入，所以欢迎帮助），或者这种拓扑结构是否不可能实现，因为我必须以某种方式将新服务器定义为网络中每台机器路由中媒体中心的网关？
额外细节 ：
me@newserver:~$ ip -br link
lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP>
eno1 UP 00:22:19:cc:db:0c <BROADCAST,MULTICAST,UP,LOWER_UP>
eno2 UP 00:22:19:cc:db:0e <BROADCAST,MULTICAST,UP,LOWER_UP>
eno3 DOWN 00:22:19:cc:db:10 <BROADCAST,MULTICAST>
eno4 DOWN 00:22:19:cc:db:12 <BROADCAST,MULTICAST>
br0 UP 76:1b:8c:b8:3a:15 <BROADCAST,MULTICAST,UP,LOWER_UP>
docker0 DOWN 02:42:17:43:24:12 <NO-CARRIER,BROADCAST,MULTICAST,UP>
me@newserver:~$ ip -br a
lo UNKNOWN 127.0.0.1/8 ::1/128
eno1 UP
eno2 UP
eno3 DOWN
eno4 DOWN
br0 UP 192.168.0.4/24 fe80::741b:8cff:feb8:3a15/64
docker0 DOWN 172.17.0.1/16 fe80::42:17ff:fe43:2412/64
me@newserver:~$ cat /proc/net/arp
IP address HW type Flags HW address Mask Device
192.168.0.21 0x1 0x2 44:8a:5b:f1:d5:fb * br0
192.168.0.3 0x1 0x2 b8:27:eb:da:cb:20 * br0
192.168.0.1 0x1 0x2 a0:1b:29:7d:d9:73 * br0
192.168.0.2 0x1 0x2 d4:9a:20:c2:c8:c8 * br0
me@newserver:~$ bridge link
2: eno1 state UP : <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br0 state forwarding priority 32 cost 19
3: eno2 state UP : <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br0 state forwarding priority 32 cost 19
me@newserver:~$ sudo iptables-save -c
# Generated by iptables-save v1.6.1 on Sun Jan 27 10:52:29 2019
*nat
:PREROUTING ACCEPT [213193:40208006]
:INPUT ACCEPT [3463:1018938]
:OUTPUT ACCEPT [766:58537]
:POSTROUTING ACCEPT [766:58537]
:DOCKER - [0:0]
[45:2724] -A PREROUTING -m addrtype --dst-type LOCAL -j DOCKER
[1:60] -A OUTPUT ! -d 127.0.0.0/8 -m addrtype --dst-type LOCAL -j DOCKER
[0:0] -A POSTROUTING -s 172.17.0.0/16 ! -o docker0 -j MASQUERADE
[0:0] -A DOCKER -i docker0 -j RETURN
COMMIT
# Completed on Sun Jan 27 10:52:29 2019
# Generated by iptables-save v1.6.1 on Sun Jan 27 10:52:29 2019
*filter
:INPUT ACCEPT [44978969:67464645682]
:FORWARD DROP [130478:14923761]
:OUTPUT ACCEPT [23637250:1293021280]
:DOCKER - [0:0]
:DOCKER-ISOLATION-STAGE-1 - [0:0]
:DOCKER-ISOLATION-STAGE-2 - [0:0]
:DOCKER-USER - [0:0]
[130478:14923761] -A FORWARD -j DOCKER-USER
[130478:14923761] -A FORWARD -j DOCKER-ISOLATION-STAGE-1
[0:0] -A FORWARD -o docker0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
[0:0] -A FORWARD -o docker0 -j DOCKER
[0:0] -A FORWARD -i docker0 ! -o docker0 -j ACCEPT
[0:0] -A FORWARD -i docker0 -o docker0 -j ACCEPT
[0:0] -A DOCKER-ISOLATION-STAGE-1 -i docker0 ! -o docker0 -j DOCKER-ISOLATION-STAGE-2
[130478:14923761] -A DOCKER-ISOLATION-STAGE-1 -j RETURN
[0:0] -A DOCKER-ISOLATION-STAGE-2 -o docker0 -j DROP
[0:0] -A DOCKER-ISOLATION-STAGE-2 -j RETURN
[130478:14923761] -A DOCKER-USER -j RETURN
COMMIT
# Completed on Sun Jan 27 10:52:29 2019
me@newserver:~$ sudo bridge monitor
a0:1b:29:7d:d9:74 dev eno1 master br0
a0:1b:29:7d:d9:72 dev eno1 master br0
Deleted a0:1b:29:7d:d9:74 dev eno1 master br0 stale
Deleted 78:67:d7:21:56:34 dev eno1 master br0 stale
78:67:d7:21:56:34 dev eno1 master br0
a0:1b:29:7d:d9:74 dev eno1 master br0
dev br0 port eno1 grp ff02::fb temp
Deleted a0:1b:29:7d:d9:72 dev eno1 master br0 stale
Deleted 30:07:4d:3e:2f:bb dev eno1 master br0 stale
98:b6:e9:cd:fb:4a dev eno1 master br0
Deleted a0:1b:29:7d:d9:74 dev eno1 master br0 stale
Deleted dev br0 port eno1 grp ff02::fb temp
Deleted dev br0 port br0 grp ff02::fb temp
bridge-netfilter没有安装，而且据我所知没有过滤（基本上是全新安装 + docker）
答案1
确实可以实现这样的网络设置，并且 netplan 配置正确。问题实际上来自 iptable，它丢弃了通过网桥的数据包。有关此问题的更多详细信息，请参见此处
解决办法很简单，就是在桥上接受数据包：
me@newserver:~$ sudo iptables -A FORWARD -p all -i br0 -j ACCEPT
（并使更改永久生效：
me@newserver:~# iptables-save > /etc/iptables/rules.v4
）