Virtual Networks Introduction

Layer 2 VLAN ID on the switch that the VN is assigned to.

If left blank, it's auto-assigned from static pool (2-4094).

If you assign it, we don't recommend assigning VLAN ID 1 for active VNs.

Cisco NX-OS reserves VLAN IDs 3968-4094.

Arista reserves 1006-4094 for internal VLANs for routed ports. You can modify "reserved" VLAN ID range with the EOS vlan internal allocation policy configuration command. You can apply it to all EOS devices using a SYSTEM configlet before configuring and deploying VNs.

l2-virtual-ext-002-leaf1(config)#vlan internal allocation policy ascending range 3001 3999
l2-virtual-ext-002-leaf1(config)#exit
l2-virtual-ext-002-leaf1#show vlan internal allocation policy
Internal VLAN Allocation Policy: ascending
Internal VLAN Allocation Range: 3001-3999
l2-virtual-ext-002-leaf1#

Using reserved VLAN IDs may cause deployment errors, but not build errors.

Enabled (default) - Apstra decides whether a secondary IP address is needed.

• Automatically allocate if an assigned connectivity template requires an address (BGP, Static routes).

• VN of type VXLAN:

  • Some NOS types automatically allocate unicast IPv4 addresses when an anycast IPv4 gateway is present: (Junos when in an ESI pair).

  • If a NOS type forbids co-existence of an anycast IPv4 address with an unicast IPv4 address, a blueprint error will be raised (Sonic).

• VN of type VLAN - All NOS types require unicast IPv4 addresses when the IPv4 anycast address is enabled.

Forced - A secondary IP address is rendered irrespective of whether or not a connectivity template requires it.

• If a NOS type forbids co-existence of an anycast IPv4 address with a unicast IPv4 address, a blueprint error will be raised.

• Permits you to manually create an optional unicast IPv4 address for purposes such as BGP peering or static routing.