Dynamic Virtual Networks

ExtremeXOS 30.3 introduces the ability to globally enable dynamic virtual network creation by using the following command:

configure virtual-network dynamic [on | off]

Dynamic virtual network is disabled by default. Creating or deleting BGP Auto-peering enables/disables automatic virtual network creation.

The status of this command is visible in the following command:

show virtual-network {vn_name | vxlan vni vni | [vlan vlan_name | vman vman_name]}

When this feature is enabled, the following occurs for a new VLAN-NSI mapping:
  1. A dynamic virtual network is created. The virtual network name is generated with a system reserved prefix.
  2. VXLAN VNI is configured for the virtual network. The VNID is same as the value of NSI.
  3. The VLAN is configured as a tenant VLAN.

When a VLAN-NSI mapping is deleted, the dynamically created virtual network along with the VNI and VLAN associations are purged.

Dynamic Virtual Networks Properties

  • All restrictions for static virtual network, both configuration and functional, also apply to dynamic virtual networks.
  • A dynamic virtual network is not saved to the configuration and is not persistent across reboots.
  • IGMP snooping is internally disabled for a VLAN dynamically configured as tenant VLAN of a virtual network.
  • When a dynamic virtual network is renamed, it becomes static and can be saved to the configuration.
  • You can delete a dynamic virtual network from the CLI. It is recreated if dynamic virtual network feature is on, and the conditions are met.
  • The default reserved prefix pattern for a dynamic virtual network name is SYS_VNET_xxxxxxxx, where xxxxxxxx is VNID (in the lines of dynamic VLANs – SYS_VLAN_xxxx).
  • If SYS_VNET_ prefix is already in use by virtual networks in an older configuration, best effort is made to choose one of the following non-conflicting prefixes – SYS_VNET_DYN_, SYS_VNET_AUTO_, SYS_VNET_AUTOGEN_.