Running KVM using the Openvswitch one way to attach VMs to the network. When using libvirt 1.02 and higher, several configuration options are available. The virt-manager can only use openvswitch fake bridges, so the virt-manager is not the best tool to configure the network interfaces for VM’s.<\/p>\n
There are two ways to define libvirt networks:<\/p>\n
The configuration can be split info different parts. One part is the generic part covering the basic interface configuration. The extended part convers the type of the link (untagged or tagged) and the assignment to one or more vlans.<\/p>\n
The configuration should be added using „virsh edit <vmname><\/strong>„. For the examples here, I will use the name vmtest<\/em>.<\/p>\n The generic part looks like the following section:<\/p>\n The parameters are:<\/p>\n If you want to stick the VM to one vlan on the openvswitch, the generic configuration must be extended by four lines lines:<\/p>\n The parameters are:<\/p>\n The openvswitch will drop all tagged packets. This is the default setup, that you want to use, when running VMs.<\/p>\n If you want the VM to access multiple vlans on the openvswitch, the generic configuration must be extended by the following lines:<\/p>\n The parameters are:<\/p>\n If you omit the vlan and tag lines, you are creating a link, which transports untagged packets AND tagged packets allowing ALL vlans.<\/p>\n The complete configuration for our VM is now:<\/p>\n As with libvirt 1.02, it is not possible to use one vlan as the native vlan. Later libvirt versions support this. When a version is available for Ubuntu, I’ll add the necessaty section.<\/p>\n The other method is to split the network configuration. The global part, which is the same for many VMs, can be defined using the virsh net-* commands. For the first network the procedure would be:<\/p>\n Create an xml file (example name here mgmt.xml) using an editor of your choice. The file for the untagged interface should look like:<\/p>\n The parameters are:<\/p>\n Then you must „import“ the network definition to libvirt using the commands:<\/p>\n The interface configuration for the VM should be changed to use the created network<\/p>\n This looks much simpler now compared to the section above. The parameters are:<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Running KVM using the Openvswitch one way to attach VMs to the network. When using libvirt 1.02 and higher, several configuration options are available. The virt-manager can only use openvswitch fake bridges, so the virt-manager is not the best tool to configure the network interfaces for VM’s. There are two ways to define libvirt networks: […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,4],"tags":[],"_links":{"self":[{"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=\/wp\/v2\/posts\/177"}],"collection":[{"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=177"}],"version-history":[{"count":11,"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=\/wp\/v2\/posts\/177\/revisions"}],"predecessor-version":[{"id":234,"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=\/wp\/v2\/posts\/177\/revisions\/234"}],"wp:attachment":[{"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=177"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=177"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.opencloudblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}The generic part<\/h2>\n
<interface type='bridge'>\r\n <virtualport type='openvswitch'>\r\n <\/virtualport>\r\n <target dev='veth0-vmtest'\/>\r\n <model type='virtio'\/>\r\n <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'\/>\r\n <\/interface><\/pre>\n
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An untagged port<\/h2>\n
<source bridge='brtest'\/>\r\n <vlan>\r\n <tag id='2001'\/>\r\n <\/vlan><\/pre>\n
\n
A tagged port with a restricted vlan list<\/h2>\n
<source bridge='brtest-ext'\/>\r\n <vlan trunk='yes'>\r\n <tag id='2102'\/>\r\n <tag id='2103'\/>\r\n <tag id='2110'\/>\r\n <tag id='2999'\/>\r\n <tag id='3000'\/>\r\n <\/vlan><\/pre>\n
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The complete configuration<\/h2>\n
<interface type='bridge'>\r\n <source bridge='brtest'\/>\r\n <vlan>\r\n <tag id='2001'\/>\r\n <\/vlan> \r\n <virtualport type='openvswitch'>\r\n <\/virtualport>\r\n <target dev='veth0-vmtest'\/>\r\n <model type='virtio'\/>\r\n <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'\/>\r\n <\/interface>\r\n\r\n <interface type='bridge'>\r\n <source bridge='brtest-ext'\/>\r\n <vlan trunk='yes'>\r\n <tag id='2102'\/>\r\n <tag id='2103'\/>\r\n <tag id='2110'\/>\r\n <tag id='2999'\/>\r\n <tag id='3000'\/>\r\n <\/vlan>\r\n <virtualport type='openvswitch'>\r\n <\/virtualport>\r\n <target dev='veth1-vmtest'\/>\r\n <model type='virtio'\/>\r\n <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'\/>\r\n <\/interface><\/pre>\n
Native vlan<\/h2>\n
Define libvirt networks<\/h1>\n
<network>\r\n <name>Mgmt-2001<\/name>\r\n <forward mode='bridge'\/>\r\n <bridge name='brtest' \/>\r\n <virtualport type='openvswitch'>\r\n <\/virtualport>\r\n <vlan>\r\n <tag id='2001'\/>\r\n <\/vlan>\r\n<\/network><\/pre>\n
\n
#\r\n# import the net config to libvirt\r\nvirsh net-define mgmt.xml\r\n#\r\n# start the new network - necessary to use it in libvirt\r\n# this DOES NOT create or touch the bridge!\r\n# this is only for the internal libvirt management\r\nvirsh net-start Mgmt-2001\r\n#\r\n# do not forget to set autostart for the network\r\n# if you forget this, the network will not be available after\r\n# the next system boot or libvirt restart\r\nvirsh net-autostart Mgmt-2001\r\n#\r\n# verify the status of the network\r\nvirsh net-list<\/pre>\n
<interface type='network'>\r\n <source network='Mgmt-2001'\/>\r\n <target dev='veth0-test1'\/>\r\n <model type='virtio'\/>\r\n <\/interface><\/pre>\n
\n