I use tap mode for the guest network in qemu . here is /etc/sysconfig/network-scripts/ifcfg-br0 2 DEVICE=br0 3 TYPE=Bridge 4 BOOTPROTO=static 5 ONBOOT=yes 6 DNS1=192.168.1.1 7 GATEWAY=10.16.255.254 8 IPADDR=10.16.172.77 9 NETMASK=255.255.0.0 10 ONBOOT=yes 11 DELAY=0 12 STP=off (line number) /etc/sysconfig/network-scripts/ifcfg-em1 1 DEVICE="em1" 2 ONBOOT=yes 3 HWADDR= 4 NM_CONTROLLED="no" 5 TYPE=Ethernet 6 PREFIX=24 7 DEFROUTE=yes 8 IPV4_FAILURE_FATAL=yes 9 IPV6INIT=no 10 NAME="System em1" 11 UUID=1dad842d-1912-ef5a-a43a-bc238fb267e7 12 BRIDGE=br0 use a sh script to biuld tap 3 tunctl -t tap0 -u root 4 brctl addif br0 tap0 5 ifconfig tap0 up 6 ifconfig tap0 0.0.0.0 promisc up qemu use like -net nic -net tap Make guest os ip 10.16.172.18 netmask:255.255.0.0 gateway:10.16.255.254 dns: 192.168.1.1 Here is i got problem . guest ping www.google.com is ok but host os ping 10.16.172.78 get error: PING 10.1.172.78 (10.1.172.78) 56(84) bytes of data. >From 10.1.1.9 icmp_seq=1 Time to live exceeded >From 10.1.1.9 icmp_seq=2 Time to live exceeded >From 10.1.1.9 icmp_seq=3 Time to live exceeded >From 10.1.1.9 icmp_seq=4 Time to live exceeded First I got the ip from company ,which mean i can have the network 10.16.172.0 using br0 as bridge .The guest os can have a ip 10.16.172.78 (manly set) The error show , 10.1.1.9 was a router which don't know the ip 10.16.172.78 ? I can't ping the guest os , but that's why i use tap mode in qemu .Because qemu stack mode also can connect to outside. but wasn't seen in host os . I think don't need ask system manager to set it . Am i right ? How can i make host ping the guest rightly ? -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org