In earlier posts I installed the KVM hypervisor on an openSUSE Leap system and added a bridged network connection. That will allow virtual machines to use IP addresses on my house network. However, what if I want to use ‘private’ networks for the experiments I wish to run? That is easily done so let’s see how to create networks and address ranges as follows:
'management'192.168.99.0/24'site1'192.168.100.0/24'site2vlan1'192.168.101.0/24'site2vlan2'192.168.102.0/24
Bring up the ‘details’ pane for the hypervisor and select the ‘Virtual Networks’ tab as follows:

Clicking on the small blue cross opens the dialog for adding a new network. Let’s define the ‘management’ LAN as follows:

Next, define the IP address and subnet mask (192.168.99.0/24) and untick the ‘Enable DHCPv4’ option. DHCP will be provided by the virtual Mikrotek router.

On the next pane, disable IPv6 for the time being.

Finally, select the option to create an isolated network and keep the DNS Domain Name as shown.

Repeating the process for the other networks produces a network list as follows:

As a final check to see that everything is working as expected, bring up a console as the root user and type the following commands:
virsh net-list
virsh net-list Name State Autostart Persistent ---------------------------------------------------------- management active yes yes site1 active yes yes site2vlan1 active yes yes site2vlan2 active yes yes
ip addr
ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000 link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff 3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff inet 192.168.1.101/24 brd 192.168.1.255 scope global br0 valid_lft forever preferred_lft forever inet6 fd00::1:8ca0:7c31:ae16:2e0e/64 scope global temporary dynamic valid_lft 6233sec preferred_lft 6233sec inet6 fd00::1:12bf:48ff:fe88:f355/64 scope global mngtmpaddr dynamic valid_lft 6233sec preferred_lft 6233sec inet6 fe80::12bf:48ff:fe88:f355/64 scope link valid_lft forever preferred_lft forever 4: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:c4:63:38 brd ff:ff:ff:ff:ff:ff inet 192.168.99.1/24 brd 192.168.99.255 scope global virbr0 valid_lft forever preferred_lft forever 5: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:c4:63:38 brd ff:ff:ff:ff:ff:ff 6: virbr1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:53:8a:0c brd ff:ff:ff:ff:ff:ff inet 192.168.100.1/24 brd 192.168.100.255 scope global virbr1 valid_lft forever preferred_lft forever 7: virbr1-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr1 state DOWN group default qlen 1000 link/ether 52:54:00:53:8a:0c brd ff:ff:ff:ff:ff:ff 8: virbr2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:cf:6f:e2 brd ff:ff:ff:ff:ff:ff inet 192.168.101.1/24 brd 192.168.101.255 scope global virbr2 valid_lft forever preferred_lft forever 9: virbr2-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr2 state DOWN group default qlen 1000 link/ether 52:54:00:cf:6f:e2 brd ff:ff:ff:ff:ff:ff 10: virbr3: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:26:84:24 brd ff:ff:ff:ff:ff:ff inet 192.168.102.1/24 brd 192.168.102.255 scope global virbr3 valid_lft forever preferred_lft forever 11: virbr3-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr3 state DOWN group default qlen 1000 link/ether 52:54:00:26:84:24 brd ff:ff:ff:ff:ff:ff
The results show the four virtual networks (virbr0 to virbr3)
, but they also show that four virtual network adapters (virbr0-nic to virbr3-nic)
have been created that connect each of these new networks to the host machine itself.
In another post, the virtual Mikrotek router will be installed and a basic configuration applied to allow it to route between the four virtual networks.