Blade ICE G8124-E Manuale Utente

BMD00220, October 2010

Chapter 12: Virtual NICs  

  157

vNICs can be grouped together, along with uplink ports and trunks, as well as other ports that were 
defined as server ports but not connected to vNICs. Each vNIC group is essentially a separate 
virtual network within the switch. Elements within a vNIC group have a common logical function 
and can communicate with each other, while elements in different vNIC groups are separated.

BLADEOS 6.5 supports up to 32 independent vNIC groups.

To enforce group boundaries, each vNIC group is assigned its own unique VLAN. The vNIC group 
VLAN ID is placed on all vNIC group packets as an “outer” tag. As shown in 

, the outer 

vNIC group VLAN ID is placed on the packet in addition to any regular VLAN tag assigned by the 
network, server, or hypervisor. The outer vNIC group VLAN is used only between the G8124 and 
the NIC.

Outer and Inner VLAN Tags

Within the G8124, all Layer 2 switching for packets within a vNIC group is based on the outer 
vNIC group VLAN. The G8124 does not consider the regular, inner VLAN ID (if any) for any 
VLAN-specific operation.

The outer vNIC group VLAN is removed by the NIC before the packet reaches the server OS or 
hypervisor, or by the switch before the packet egresses any switch port which does not need it for 
vNIC processing.

The VLAN configured for the vNIC group will be automatically assigned to member vNICs, ports, 
and trunks and should not be manually configured for those elements.

Once a VLAN is assigned to a vNIC group, that VLAN is used only for vNIC purposes and 

is no longer available for configuration. Likewise, any VLAN configured for regular purposes 
cannot be configured as a vNIC group VLAN.

Outbound

Packet

Inbound

Packet

Regular
VLAN ID

NIC attached outer
vNIC group VLAN ID

Switch adds outer

vNIC group VLAN ID

Outer tag sets vNIC;
NIC strips outer tag

Switching uses outer tag;
Ignores regular VLAN

Switching uses outer tag;
Ignores regular VLAN

Switch strips

outer tag

OS/Hypervisor

NIC