How to give fixed IPs to guests (accessible from outside of host)?

[Peng Yu]

Hi,

https://help.ubuntu.com/13.10/serverguide/libvirt.html

I followed the instructions and I'm able to create a host and access
it. But its IP is something like 192.168.x.x, which is not accessible
outside the host. Could anybody let me know how to create a guest with
fixed IPs so that they can be accessed from outside? Thanks.

-- 
Regards,
Peng