DomU不是在跟世界说话，而是跟Dom0说话。
这是我做的testing：
Dom0（外部networking正在工作）：
ping 188.40.96.238 #Which is Domu's ip PING 188.40.96.238 (188.40.96.238) 56(84) bytes of data. 64 bytes from 188.40.96.238: icmp_seq=1 ttl=64 time=0.092 ms DomU的：
ping 188.40.96.215 #Which is Dom0's ip PING 188.40.96.215 (188.40.96.215) 56(84) bytes of data. 64 bytes from 188.40.96.215: icmp_seq=1 ttl=64 time=0.045 ms ping 188.40.96.193 #Which is the gateway - fail PING 188.40.96.193 (188.40.96.193) 56(84) bytes of data. ^C --- 188.40.96.193 ping statistics --- 2 packets transmitted, 0 received, 100% packet loss, time 1013ms
系统是debian lenny，并且安装正常。
这是我的configuration：
uname -a
Linux green0 2.6.26-2-xen-686 #1 SMP Wed Aug 19 08:47:57 UTC 2009 i686 GNU/Linux
cat /etc/xen/green1.cfg | grep -v'＃'
kernel = '/boot/vmlinuz-2.6.26-2-xen-686' ramdisk = '/boot/initrd.img-2.6.26-2-xen-686' memory = '2000' root = '/dev/xvda2 ro' disk = [ 'file:/home/xen/domains/green1/swap.img,xvda1,w', 'file:/home/xen/domains/green1/disk.img,xvda2,w', ] name = 'green1' vif = [ 'ip=188.40.96.238,mac=00:16:3E:1F:C4:CC' ] on_poweroff = 'destroy' on_reboot = 'restart' on_crash = 'restart'
使用ifconfig
eth0 Link encap:Ethernet HWaddr 00:24:21:ef:2f:86 inet addr:188.40.96.215 Bcast:188.40.96.255 Mask:255.255.255.192 inet6 addr: fe80::224:21ff:feef:2f86/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:3296 errors:0 dropped:0 overruns:0 frame:0 TX packets:2204 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:262717 (256.5 KiB) TX bytes:330465 (322.7 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 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) peth0 Link encap:Ethernet HWaddr 00:24:21:ef:2f:86 inet6 addr: fe80::224:21ff:feef:2f86/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:3407 errors:0 dropped:657431448 overruns:0 frame:0 TX packets:2291 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:319941 (312.4 KiB) TX bytes:338423 (330.4 KiB) Interrupt:16 Base address:0x8000 vif2.0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:27 errors:0 dropped:0 overruns:0 frame:0 TX packets:151 errors:0 dropped:33 overruns:0 carrier:0 collisions:0 txqueuelen:32 RX bytes:1164 (1.1 KiB) TX bytes:20974 (20.4 KiB)
IP为
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: peth0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:24:21:ef:2f:86 brd ff:ff:ff:ff:ff:ff inet6 fe80::224:21ff:feef:2f86/64 scope link valid_lft forever preferred_lft forever 4: vif0.0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 5: veth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 6: vif0.1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 7: veth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 8: vif0.2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 9: veth2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 10: vif0.3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 11: veth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 12: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN link/ether 00:24:21:ef:2f:86 brd ff:ff:ff:ff:ff:ff inet 188.40.96.215/26 brd 188.40.96.255 scope global eth0 inet6 fe80::224:21ff:feef:2f86/64 scope link valid_lft forever preferred_lft forever 14: vif2.0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 32 link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff inet6 fe80::fcff:ffff:feff:ffff/64 scope link valid_lft forever preferred_lft forever
brctl显示
bridge name bridge id STP enabled interfaces eth0 8000.002421ef2f86 no peth0 vif2.0
ip rl
Dom0中：
188.40.96.192/26 dev eth0 proto kernel scope link src 188.40.96.215 default via 188.40.96.193 dev eth0
DomU的：
188.40.96.192/26 dev eth0 proto kernel scope link src 188.40.96.238 default via 188.40.96.193 dev eth0
默认桥接脚本做了很多奇怪的事情，使eth0 / peth0设备..我有更好的运气在/ etc / network / interfaces中设置为
# The primary network interface auto xen-br0 iface xen-br0 inet static address 10.2.2.44 gateway 10.2.2.1 netmask 255.255.255.0 bridge_ports eth0 bridge_stp off bridge_fd 0
然后在xend-config.sxp中：
(vif-script vif-bridge bridge=xen-br0)
这样debian就可以搭起桥梁，而xen离开它。
你有接入路由器和交换机吗？ 你可以跑步，还是让别人跑步：
show ip arp 188.40.96.238 show mac-address-table address 0016.3E1F.C4CC
（或任何命令适合您的设备）这将确认您的domU是甚至可见的networking的其余部分。
确保连接dom0机器的交换机允许每个端口有多个MAC地址。 我configuration了一个cisco交换机，每个端口设置为“桌面”。 这启用了PortFast，但也禁用了端口上的多个MAC地址。 所有来自domU虚拟机的数据包都被无声地丢弃了。 在交换机内将端口设置切换回“无”解决了这个问题。
当DomU可以与dom0对话，而不是外部世界，而dom0可以通过同一个网桥，那么很有可能在dom0上有一个防火墙来捕获domU数据包。
考虑到我把这个网桥看成是一个“在networking上”的交换机，而不是在dom0的控制范围之内，我只是closures了dom0从网桥通过dom0的防火墙运行数据包的做法：
sysctl { "net.bridge.bridge-nf-call-arptables": value => "0"; "net.bridge.bridge-nf-call-iptables": value => "0"; "net.bridge.bridge-nf-call-ip6tables": value => "0"; "net.bridge.bridge-nf-filter-vlan-tagged": value => "0"; }