atomtigerzoo · May 10, 2024 08:54 · Feb 18, 2016 · Feb 18, 2016 · Feb 15, 2016 · Feb 15, 2016
diff --git a/libvirt-kvm-virtual-network.md b/libvirt-kvm-virtual-network.md
@@ -157,4 +157,12 @@ And check if you can ping the outside and your internal network on the host mach
     ping 192.168.100.1
 
 If both commands return a successful ping all went well. Return the steps for your 
-second guest now.
+second guest now.
+
+
+### Add hosts to live-network
+
+All edits to a network require a full restart of the network and all machines attached 
+to it! You can add/remove new guests to running networks with the following:
+
+    virsh net-update <NETWORKNAME> add ip-dhcp-host "<host mac='<MACADRESS>' name='<NAME_OR_FQDN>' ip='<GUEST_IP_IN_DHCP_RANGE>' />" --live --config
diff --git a/libvirt-kvm-virtual-network.md b/libvirt-kvm-virtual-network.md
@@ -54,6 +54,10 @@ If you want to take a look at the new network:
 
     EDITOR=nano virsh net-edit internal
 
+If you already had a network called internal (or want to stop another) use
+
+    virsh net-destroy <NETWORK_NAME>
+
 Let's start the network:
 
     virsh net-start internal
@@ -84,7 +88,7 @@ and add a new interface.
 Replace the uppercase strings with a) the name of your first vm to edit and b) 
 the MAC address from above for guest 1 and run it:
 
-    virsh attach-interface --domain <NAME_OF_GUEST_1_VM> --type network --source internal --model virtio --mac <YOUR_RANDOM_MAC_ADDRESS_FOR_GUEST_1> --config
+    virsh attach-interface --domain <NAME_OF_GUEST_1_VM> --type network --source internal --model virtio --mac <YOUR_RANDOM_MAC_ADDRESS_FOR_GUEST_1> --config --live
 
 It should yield *Interface attached successfully*. Repeat the command by replacing 
 the guest name and the MAC address with the ones for the second vm, guest 2.

diff --git a/libvirt-kvm-virtual-network.md b/libvirt-kvm-virtual-network.md
@@ -109,7 +109,48 @@ down, don't restart them. Otherwise the network and NIC won't be attached.
 Check if they are down and if they are, boot them up again:
 
     virsh list --all
-    
+
     virsh start <NAME_OF_GUEST_1_VM>
     virsh start <NAME_OF_GUEST_2_VM>
 
+
+### Add network to guests
+Now we will add the newly created interface to each guest. This means you will have to 
+repeat this step for each guest, replacing the MAC and IP accordingly.
+
+Log into the guest:
+
+    virsh console <NAME_OF_GUEST_1_VM>
+
+Check for the NIC:
+
+    ip a
+
+There should be an empty interface. Note the name of it. If the VM had network access 
+before it should be *eth1*. If you already have multiple interfaces, I think you know 
+what you are doing ;)
+
+Let's add the choosen static IP to:
+
+    nano /etc/network/interfaces
+
+    [... lo ... eth0 ...]
+
+    auto eth1
+    iface eth1 inet static
+        address       192.168.100.2
+        gateway       192.168.100.1
+        netmask       255.255.255.0
+
+Save it and close it. Restart the networking afterwards with:
+
+    /etc/init.d/networking restart
+
+And check if you can ping the outside and your internal network on the host machine:
+
+    ping github.com
+
+    ping 192.168.100.1
+
+If both commands return a successful ping all went well. Return the steps for your 
+second guest now.
diff --git a/libvirt-kvm-virtual-network.md b/libvirt-kvm-virtual-network.md
@@ -6,7 +6,7 @@ installed. You need two guest VMs for this. The first guest will get the IP
 must be run with `sudo` or under root.
 
 
-### internal Network
+### Internal Network
 We create a new network named **internal** with libvirt and use it with the IP
 range of 192.168.100.2 - 192.168.100.254 to build our private network.
 
@@ -101,4 +101,15 @@ It should show something like:
     -          network    internal   virtio      YOUR_CREATED_MAC_ADDRESS
 
 Perfect. Now, if the guests are running please shut them down - and I mean shut the
-down, don't restart them.
+down, don't restart them. Otherwise the network and NIC won't be attached.
+
+    virsh shutdown <NAME_OF_GUEST_1_VM>
+    virsh shutdown <NAME_OF_GUEST_2_VM>
+
+Check if they are down and if they are, boot them up again:
+
+    virsh list --all
+
+    virsh start <NAME_OF_GUEST_1_VM>
+    virsh start <NAME_OF_GUEST_2_VM>
+
diff --git a/libvirt-kvm-virtual-network.md b/libvirt-kvm-virtual-network.md
@@ -10,8 +10,8 @@ must be run with `sudo` or under root.
 We create a new network named **internal** with libvirt and use it with the IP
 range of 192.168.100.2 - 192.168.100.254 to build our private network.
 
-For the network and the two guest VMs we need MAC addresses. Create them three 
-random MACs with:
+For the network and the two guest VMs we need MAC addresses. Create three 
+random MACs with: (you must run it three times ;))
 
     MACADDR="52:54:00:$(dd if=/dev/urandom bs=512 count=1 2>/dev/null | md5sum | sed 's/^\(..\)\(..\)\(..\).*$/\1:\2:\3/')"; echo $MACADDR
 
@@ -68,7 +68,37 @@ You should see an output like:
     64 bytes from 192.168.100.1: icmp_seq=1 ttl=64 time=0.065 ms
     64 bytes from 192.168.100.1: icmp_seq=2 ttl=64 time=0.049 ms
 
-Stop it with ctrl+c. Great let's move on and create the NICs for the guests.
+Stop it with ctrl+c. 
+
+If you want to autostart the internal network with boot, run:
+
+    virsh net-autostart internal
+
 
 
 ### Guest NICs
+
+Let's move on and create NICs for the each guest. We open the config of each VM
+and add a new interface.
+
+Replace the uppercase strings with a) the name of your first vm to edit and b) 
+the MAC address from above for guest 1 and run it:
+
+    virsh attach-interface --domain <NAME_OF_GUEST_1_VM> --type network --source internal --model virtio --mac <YOUR_RANDOM_MAC_ADDRESS_FOR_GUEST_1> --config
+
+It should yield *Interface attached successfully*. Repeat the command by replacing 
+the guest name and the MAC address with the ones for the second vm, guest 2.
+
+You can check out the new NICs with:
+
+    virsh domiflist <NAME_OF_GUEST_1_VM>
+    virsh domiflist <NAME_OF_GUEST_2_VM>
+
+It should show something like:
+
+    Interface  Type       Source     Model       MAC
+    -------------------------------------------------------
+    -          network    internal   virtio      YOUR_CREATED_MAC_ADDRESS
+
+Perfect. Now, if the guests are running please shut them down - and I mean shut the
+down, don't restart them.
diff --git a/libvirt-kvm-virtual-network.md b/libvirt-kvm-virtual-network.md
@@ -38,8 +38,37 @@ Paste the following template:
       </ip>
     </network>
 
+Now replace the uppercase strings with your created MAC addresses and save the file.
 
+**Hint** I have called the bridge *virbr1* because in most cases you will already have
+another network (virbr0). If you have multiple networks or bridges please select an
+unused name. Otherwise you will get an error while creating or starting the network.
 
-### Guests
-
-#### Create new NICs
+Now let us define/load the new network:
+
+    virsh net-define /etc/libvirt/qemu/networks/internal.xml
+
+From now on, if you want to edit your new network you must use `virsh net-edit` otherwise
+all changes will be overwritten (there is a warning if you open the file with a normal editor).
+If you want to take a look at the new network:
+
+    EDITOR=nano virsh net-edit internal
+
+Let's start the network:
+
+    virsh net-start internal
+
+You should now be able to ping the first IP of the created range:
+
+    ping 192.168.100.1
+
+You should see an output like:
+
+    PING 192.168.100.1 (192.168.100.1) 56(84) bytes of data.
+    64 bytes from 192.168.100.1: icmp_seq=1 ttl=64 time=0.065 ms
+    64 bytes from 192.168.100.1: icmp_seq=2 ttl=64 time=0.049 ms
+
+Stop it with ctrl+c. Great let's move on and create the NICs for the guests.
+
+
+### Guest NICs
diff --git a/libvirt-kvm-virtual-network.md b/libvirt-kvm-virtual-network.md
@@ -0,0 +1,45 @@
+## Create private networks with libvirt
+
+I assume that you have a running debian wheezy host with libvirt and qemu/kvm 
+installed. You need two guest VMs for this. The first guest will get the IP 
+192.168.100.2 and the second will get 192.168.100.100. All following commands 
+must be run with `sudo` or under root.
+
+
+### internal Network
+We create a new network named **internal** with libvirt and use it with the IP
+range of 192.168.100.2 - 192.168.100.254 to build our private network.
+
+For the network and the two guest VMs we need MAC addresses. Create them three 
+random MACs with:
+
+    MACADDR="52:54:00:$(dd if=/dev/urandom bs=512 count=1 2>/dev/null | md5sum | sed 's/^\(..\)\(..\)\(..\).*$/\1:\2:\3/')"; echo $MACADDR
+
+Copy all three to a text editor for later usage. Label the first *internal network*
+and the other tow *guest 1* and *guest 2* for reference.
+
+Let's create the network. Open a new file:
+
+    nano /etc/libvirt/qemu/networks/internal.xml
+
+Paste the following template:
+
+    <network>
+      <name>internal</name>
+      <forward mode='nat'/>
+      <bridge name='virbr1' stp='on' delay='0'/>
+      <mac address='YOUR_RANDOM_MAC_ADDRESS_FOR_THE_NETWORK'/>
+      <ip address='192.168.100.1' netmask='255.255.255.0'>
+        <dhcp>
+          <range start='192.168.100.2' end='192.168.122.254'/>
+          <host mac='YOUR_RANDOM_MAC_ADDRESS_FOR_GUEST_1' ip='192.168.100.2'/>
+          <host mac='YOUR_RANDOM_MAC_ADDRESS_FOR_GUEST_2' ip='192.168.100.100'/>
+        </dhcp>
+      </ip>
+    </network>
+
+
+
+### Guests
+
+#### Create new NICs