• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/sect-Virtualization_Host_Configuration_and_Guest_Installation_Guide-Host_Installation-Installing_KVM_packages_on_an_existing_Red_Hat_Enterprise_Linux_system.html

[root@localhost ~]# yum groupinstall Virtualization
[root@localhost ~]# yum groupinstall "Virtualization Client"

[root@localhost ~]# service libvirtd status

[root@localhost ~]# qemu-img create -f qcow2 /vm/kvm/pfsense.qcow2 10G


[root@localhost iso]# virt-install --vcpus=1 --ram=1024 --name=pfsense --file=/vm/kvm/pfsense.qcow2 --cdrom=/vm/iso/pfSense-CE-2.3.2-RELEASE-amd64.iso --hvm --vnc --network bridge:virbr0

[root@localhost ~]# brctl show
bridge name	bridge id		STP enabled	interfaces
virbr0		8000.5254005d4f0b	yes		virbr0-nic
							vnet0
[root@localhost ~]# ip addr
...
3: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
    link/ether 52:54:00:5d:4e:0a brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 1000
    link/ether 52:54:00:5d:4e:0a brd ff:ff:ff:ff:ff:ff
6: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master virbr0 state UNKNOWN qlen 1000
    link/ether fe:54:00:ad:70:82 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:fead:7082/64 scope link 
       valid_lft forever preferred_lft forever



[root@localhost ~]# nmap -sP 192.168.122.0/24

Starting Nmap 6.40 ( http://nmap.org ) at 2016-12-18 13:04 CET
Nmap scan report for 192.168.122.148
Host is up (0.00021s latency).
MAC Address: 52:54:00:AD:70:82 (QEMU Virtual NIC)
Nmap scan report for 192.168.122.1
Host is up.
Nmap done: 256 IP addresses (2 hosts up) scanned in 4.68 seconds
[root@localhost ~]# nmap 192.168.122.148

Starting Nmap 6.40 ( http://nmap.org ) at 2016-12-18 13:05 CET
Nmap scan report for 192.168.122.148
Host is up (0.00030s latency).
Not shown: 997 filtered ports
PORT    STATE SERVICE
22/tcp  open  ssh
80/tcp  open  http
443/tcp open  https
MAC Address: 52:54:00:AD:70:82 (QEMU Virtual NIC)

• https://wiki.libvirt.org/page/VirtualNetworking
• https://seravo.fi/2012/virtualized-bridged-networking-with-macvtap
• https://www.techotopia.com/index.php/Creating_a_CentOS_6_KVM_Networked_Bridge_Interface
• http://www.rendoumi.com/xu-ni-hua-wang-luo-bi-jiao-tun-tap-macvlan-macvtap/

[root@localhost ~]# virsh net-dumpxml default
<network>
  <name>default</name>
  <uuid>048b8b48-18f5-4100-a708-c19df66bfabd</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:5d:4f:0b'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
    </dhcp>
  </ip>
</network>

locatio of xml file

[root@localhost ~]# ls  /etc/libvirt/qemu/networks/
autostart  default.xml

lancé automatiquement par libvirt pour assurer la passralle DNS/DHCP

[root@localhost ~]# cat /var/lib/libvirt/dnsmasq/default.conf
##WARNING:  THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
##OVERWRITTEN AND LOST.  Changes to this configuration should be made using:
##    virsh net-edit default
## or other application using the libvirt API.
##
## dnsmasq conf file created by libvirt
strict-order
pid-file=/var/run/libvirt/network/default.pid
except-interface=lo
bind-dynamic
interface=virbr0
dhcp-range=192.168.122.2,192.168.122.254
dhcp-no-override
dhcp-lease-max=253
dhcp-hostsfile=/var/lib/libvirt/dnsmasq/default.hostsfile
addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts
[root@localhost ~]# cat /var/lib/libvirt/dnsmasq/default.hostsfile

• https://doc.opensuse.org/documentation/leap/virtualization/html/book.virt/cha.libvirt.networks.html
• https://kashyapc.fedorapeople.org/virt/create-a-new-libvirt-bridge.txt

definition manuelle du nouveau reseau

[root@localhost ~]# cat /root/p4p1-net.xml 
<network>
 <name>p4p1_routed</name>
 <bridge name="virbr1" />
 <forward mode="route" dev="p4p1"/>


 <ip address="192.168.22.1" netmask="255.255.255.0">
  <dhcp>
   <range start="192.168.22.2" end="192.168.22.254" />
  </dhcp>
 </ip>
</network>

[root@localhost ~]# virsh net-list --all
 Nom                  État      Démarrage automatique Persistent
----------------------------------------------------------
 default              actif      yes           yes

[root@localhost ~]# virsh net-define p4p1-net.xml
Réseau p4p1_routed défini depuis p4p1-net.xml

[root@localhost ~]# virsh net-list --all
 Nom                  État      Démarrage automatique Persistent
----------------------------------------------------------
 default              actif      yes           yes
 p4p1_routed          inactif    no            yes

[root@localhost ~]# virsh net-start p4p1_routed
Réseau p4p1_routed démarré

[root@localhost ~]# virsh net-list --all
 Nom                  État      Démarrage automatique Persistent
----------------------------------------------------------
 default              actif      yes           yes
 p4p1_routed          actif      no            yes

[root@localhost ~]# virsh net-autostart p4p1_routed
Réseau p4p1_routed marqué en démarrage automatique

[root@localhost ~]# virsh net-list --all
 Nom                  État      Démarrage automatique Persistent
----------------------------------------------------------
 default              actif      yes           yes
 p4p1_routed          actif      yes           yes

[root@localhost ~]# ls  /etc/libvirt/qemu/networks/
autostart  default.xml  p4p1_routed.xml
[root@localhost ~]# cat /etc/libvirt/qemu/networks/p4p1_routed.xml
<!--
WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
OVERWRITTEN AND LOST. Changes to this xml configuration should be made using:
  virsh net-edit p4p1_routed
or other application using the libvirt API.
-->

<network>
  <name>p4p1_routed</name>
  <uuid>1d3ddaa8-dffc-4194-a680-07680413daa2</uuid>
  <forward dev='p4p1' mode='route'>
    <interface dev='p4p1'/>
  </forward>
  <bridge name='virbr1' stp='on' delay='0'/>
  <mac address='52:54:00:f6:a6:f4'/>
  <ip address='192.168.22.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.22.2' end='192.168.22.254'/>
    </dhcp>
  </ip>
</network>
[root@localhost ~]# 

[root@localhost ~]# virsh net-list --all
 Nom                  État      Démarrage automatique Persistent
----------------------------------------------------------
 default              actif      yes           yes
 p4p1_routed          actif      yes           yes

[root@localhost ~]# virsh net-destroy p4p1_routed
Réseau p4p1_routed détruit

[root@localhost ~]# virsh net-list --all
 Nom                  État      Démarrage automatique Persistent
----------------------------------------------------------
 default              actif      yes           yes
 p4p1_routed          inactif    yes           yes

[root@localhost ~]# virsh net-undefine p4p1_routed
Le réseau p4p1_routed n'est plus défini

[root@localhost ~]# virsh net-list --all
 Nom                  État      Démarrage automatique Persistent
----------------------------------------------------------
 default              actif      yes           yes

[root@localhost ~]# ls  /etc/libvirt/qemu/networks/
autostart  default.xml

[root@localhost ~]# brctl show
bridge name	bridge id		STP enabled	interfaces
virbr0		8000.5254005d4f0b	yes		virbr0-nic
							vnet0
virbr1		8000.525400f6a6f4	yes		virbr1-nic
[root@localhost ~]# virsh attach-interface --domain pfsense --type bridge --source virbr1 --target eth2 --model virtioInterface attached successfully

[root@localhost ~]#  virsh domiflist pfsense
Interface  Type       Source     Model       MAC
-------------------------------------------------------
vnet0      bridge     virbr0     rtl8139     52:54:00:ad:7a:83
eth2       bridge     virbr1     virtio      52:54:00:c9:23:02