[libvirt-users] libvirt migrate error

hi,all when I try to migrate `vm0` from (192.168.1.102) to another host(192.168.1.200), the name `ubuntu1204` is 192.168.1.200's hostname. command is : `sudo virsh migrate --live vm0 qemu+tcp://192.168.1.200/system` the error is : unable to connect to server at 'ubuntu1204:49157': Connection refused. however,when I try to virsh connect to 192.168.1.200 by tcp is no problem. I dont know what the port 49157?how to fix it? version:libvirt:0.9.8 system:ubuntu1204 thanks in advance for any reply.