Starting in release 15.3, when a virtual machine is detected, ExtremeXOS dynamically creates the VLAN that is required for the VM to send traffic. If a virtual machine shuts down or is moved, its VLAN is pruned to preserve bandwidth. This feature creates an adaptive infrastructure in which the network responds to changes dynamically in the virtual machine network.
When a VLAN's MAC is detected on a port, XNV consults the configuration database to determine the VLAN configuration for the VM. For a case where the VM sends tagged traffic, the VLAN tag of the received frame is used to determine VLAN classification for the VM's traffic. If VLAN configuration exists for the VM and it conflicts with the actual tag present in received traffic, XNV reports an EMS message and does not trigger VLAN creation or port addition. However, if no configuration is present for the VM, XNV assumes that there are no restrictions for classifying traffic for the VM to the received VLAN.
This list determines the order of precedence for VLAN classification for untagged traffic only. For tagged VLAN traffic, XNV validates the tag of the received traffic with then VLAN tag configuration for that VM.
In addition to the VLAN tag, you can specify the VR to which the dynamically created VLAN needs to be associated. The VR configuration is relevant only if a VLAN tag is configured for the VM.
Configured VR on Port | Configured VR for VM (from VM Mapping Entry or VPP) | VLAN Already Exists on the Switch | Dynamic VLANs VR |
---|---|---|---|
None | None | No | VR-Default |
None | None | Yes | VLAN's VR |
None | VR-X | No | VR-X (Configured VR for VM) if VR-X is valid.) Otherwise an EMS error is displayed indicating the VR-X is invalid. |
None | VR-X | Yes | VLAN's VR. An EMS error is displayed if the VLAN's VR is not VR-X. |
VR-X | None | No | VR-X (Port's VR). |
VR-X | None | Yes | VR-X if VLAN's VR is VR-X. If it is not, an EMS error is displayed indicating the VR-X is invalid. |
VR-X | VR-Y | No | Dynamic VLAN is not created when Port Level VR and VM-MAC VR are different, and FDB is learned on a system generated VMAN. An EMS warning is generated on the switch log, because a Dynamic VLAN cannot be created. |
VR-X | VR-Y | Yes | VR-X if VLAN is part of VR-X. Otherwise, EMS error is displayed. |
When you disable dynamic VLAN on a port, XNV does the following:
Note
It is up to the VLAN manager to decide if the port actually needs to be removed from the VLAN.On deleting the ports from base/default VLAN the below warning message will be thrown and XNV Dynamic vlan gets disabled on that port:
Warning: Removing the untagged VLAN from a port may disrupt network connectivity. IDM and VMT may not be functional on the port without an untagged VLAN.
Note
This behavior is in effect from ExtremeXOS 16.1.create vlan v1 con v1 add ports 1untagged enable vm-tracking enable vm-tracking ports 1 enable vm-tracking dynamic-vlan ports 1 con vlan v1 delete ports 1 Warning: Removing the untagged VLAN from a port may disrupt network connectivity. IDM and VMT may not be functional on the port without an untagged VLAN. show vm-tracking ---------------------------------------------------------- VM Tracking Global Configuration ----------------------------------------------------------- VM Tracking : Enabled VM Tracking authentication order: nms vm-map local VM Tracking nms reauth period : 0 (Re-authentication disabled) VM Tracking blackhole policy : none ----------------------------------------------------------- Port : 1 VM Tracking : Enabled VM Tracking Dynamic VLAN : Disabled
When XNV is disabled on a port, the XNV dynamic VLAN feature is also disabled. The XNV dynamic VLAN configuration is not persistent, and needs to be re-enabled after XNV is re-enabled on that port.