[CentOS-virt] Second VM cannot use the network.

Fri Sep 30 03:58:56 UTC 2011
Magicloud Magiclouds <magicloud.magiclouds at gmail.com>

  I started to use libvirt and kvm yesterday. The first VM works great.
  Today I made another VM, same configuration as before. But its
network just did not work. The guest cannot even get a dhcp ip.
  The network is NAT mode. The first VM got internal ip correctly.
  The command I made the VM is:
virt-install -nzabbix1 -r2048 --vcpus=2
--os-type=linux --os-variant=rhel6 --disk vol=kvmguests/zabbix1 --vnc
-v --virt-type=kvm --check-cpu --prompt --arch=x86_64
--vnclisten= --noautoconsole --noreboot --autostart

  What should I do?