我有一台 Debian 主机，它有多个分配的 IP 和 KVM，Debian 客户机使用桥接网络。客户机完全无法访问网络，包括 LAN 甚至主机。从客户机 ping 主机会产生错误Destination Host Unreachable。如果我尝试从主机 ping 客户机，我会得到一个响应来自主机本身而不是来自客人。
主机的 /etc/network/interfaces
# The loopback network interface
auto lo
auto eth1
iface lo inet loopback
allow-hotplug eth1
iface eth1 inet static
address 108.xxx.xxx.130
netmask 255.255.255.248
network 108.xxx.xxx.128
broadcast 108.xxx.xxx.135
gateway 108.xxx.xxx.129
dns-nameservers 127.0.0.1 208.167.225.22 64.237.42.82
dns-domain example.com
# dns-* options are implemented by the resolvconf package, if installed
auto eth0
iface eth0 inet manual
auto br0
iface br0 inet static
address 108.xxx.xxx.132
netmask 255.255.255.248
bridge_ports eth0
bridge_stp on
bridge_fd 0
bridge_maxwait 0
主人的桥梁：
# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.bc5ff43b621c yes eth0
vnet0
virbr0 8000.000000000000 yes
主机的 KVM 网络：
# virsh net-list --all
Name State Autostart
-----------------------------------------
br0 active yes
default active yes
br0 网络配置：
<network>
<name>br0</name>
<uuid>cc78c850-b182-11e4-ab27-0800200c9a66</uuid>
<forward mode='bridge'/>
<bridge name='br0' />
<mac address='52:54:00:43:58:77'/>
</network>
VM的接口设置：
<interface type='bridge'>
<mac address='52:54:00:ea:c0:83'/>
<source bridge='br0'/>
<model type='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
主机的 sysctl
# sysctl -p /etc/sysctl.conf
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.all.rp_filter = 1
net.ipv4.ip_forward = 1
net.ipv4.conf.all.accept_redirects = 0
net.ipv6.conf.all.accept_redirects = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.all.accept_source_route = 0
net.ipv6.conf.all.accept_source_route = 0
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.eth0.disable_ipv6 = 1
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0
主机的 iptables：
# iptables -vnL
Chain INPUT (policy ACCEPT 16 packets, 3436 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT udp -- virbr0 * 0.0.0.0/0 0.0.0.0/0 udp dpt:53
0 0 ACCEPT tcp -- virbr0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:53
0 0 ACCEPT udp -- virbr0 * 0.0.0.0/0 0.0.0.0/0 udp dpt:67
0 0 ACCEPT tcp -- virbr0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:67
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * virbr0 0.0.0.0/0 192.168.122.0/24 state RELATED,ESTABLISHED
0 0 ACCEPT all -- virbr0 * 192.168.122.0/24 0.0.0.0/0
0 0 ACCEPT all -- virbr0 virbr0 0.0.0.0/0 0.0.0.0/0
0 0 REJECT all -- * virbr0 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable
0 0 REJECT all -- virbr0 * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable
0 0 TCPMSS tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcpflags: 0x06/0x02 TCPMSS clamp to PMTU
Chain OUTPUT (policy ACCEPT 9 packets, 832 bytes)
pkts bytes target prot opt in out source destination
访客网络设置：
auto eth0
iface eth0 inet static
address 108.xxx.xxx.132
netmask 255.255.255.248
gateway 108.xxx.xxx.129
编辑（根据 shodanshok 的回答，将主机和客户机 IP 设置为不同之后）
主机的ifconfig：
# ifconfig
br0 Link encap:Ethernet HWaddr bc:5f:f4:3b:62:1c
inet addr:108.xxx.xxx.132 Bcast:108.xxx.xxx.135 Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2584 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:594801 (580.8 KiB) TX bytes:0 (0.0 B)
eth0 Link encap:Ethernet HWaddr bc:5f:f4:3b:62:1c
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:21817 errors:0 dropped:0 overruns:0 frame:0
TX packets:493 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5806951 (5.5 MiB) TX bytes:38774 (37.8 KiB)
Interrupt:20 Memory:f7d00000-f7d20000
eth1 Link encap:Ethernet HWaddr 68:05:ca:05:f2:1e
inet addr:108.xxx.xxx.130 Bcast:108.xxx.xxx.135 Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:84560 errors:0 dropped:0 overruns:0 frame:0
TX packets:140042 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9419446 (8.9 MiB) TX bytes:157587628 (150.2 MiB)
Interrupt:16 Memory:f7cc0000-f7ce0000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:13361 errors:0 dropped:0 overruns:0 frame:0
TX packets:13361 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3897517 (3.7 MiB) TX bytes:3897517 (3.7 MiB)
virbr0 Link encap:Ethernet HWaddr 3e:14:8f:80:03:75
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
vnet0 Link encap:Ethernet HWaddr fe:54:00:ea:c0:83
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:2517 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:956 (956.0 B) TX bytes:583780 (570.0 KiB)
客人的ifconfig：
答案1
您的客人有相同的 IP 地址比主机的网桥要好。这是错误的：客户应该有一个不同的IP 地址比主机接口。
附注：这就是为什么从主机 ping 您的客户地址会导致主机本身发出答复的原因：您正在 ping 主机 IP！
尝试为您的客人配置一个班级内的免费 IP 地址（例如：108.xxx.xxx.131），它应该可以工作。
答案2
看起来您的 FORWARD 表中的 REJECT 行阻止了所有内容。
答案3
我通常像这样设置：
auto eth0
iface eth0 inet manual
auto br0
iface br0 inet manual
bridge_ports eth0
bridge_stp off
bridge_fd 9
bridge_maxage 12
bridge_hello 2
关闭客户机，然后运行 ifdown br0 && ifup br0，然后启动客户机并使用静态 IP 信息配置客户机内部的接口。