HP Virtual Connect for the Cisco Network Administrator

20
creates the SUS, adds one or more VC uplinks, defines which VLAN tags are carried on the VC
uplinks and then provides a vNet name (ASCII) for each of the VLANs defined. This means that
the uplink ports within the SUS provide external connectivity for multiple vNets. In other words,
one or more vNets share a set of uplinks for external network connectivity. This is why the term
“Shared Uplink Sets” is used. See VC Uplink 2 in the figure below.
When VC uplink ports are assigned to a single vNet and connected to an external switch
port in VLAN trunking mode, the VC uplink and vNet operate in VLAN\CoS tunneling mode or
dot1qtunnel mode by default. In other words, the vNet keeps all frames within the same layer 2
domain (vNet), however, VC allows the frames to carry different VLAN tags from the external
network all the way to the server NIC ports and vice versa. See VC Uplink 3 in the figure below.
When multiple vNETs are provisioned to a downlink a VLAN trunk is created for that connection.
The VLANs used can be from any uplinks within the Virtual Connect Domain. Up to 162 vNets
can be configured as part of this VLAN trunk. The server OS must be configured to handle
tagged traffic.
Shared Uplink Sets manage uplink redundancy the same as individual vNets do. In other
words, when multiple uplinks are assigned to a Shared Uplink Set, the uplinks can operate in
failover-only mode or they can operate in port channeling (Etherchannel) mode. Also, all VLANs
and associated vNets within a single Shared Uplink Set use the same active uplink or same
active port channel.
Note:
For sample configurations with VC connected to a Cisco switch configured for VLAN trunking,
see Virtual Connect Ethernet Cookbook: http://www.hp.com/go/bladesystem/documentation under
the “Installing” tab. The Cisco switch commands are the same for VC in VLAN Trunking mode or
VC in VLAN Tunneling mode.
Explanation of the Figure Below:
� VC Uplink 1 is assigned to vNet-PROD1-A and is operating in access mode.
� The external switch port is an access port assigned to VLAN 1.
� vNet-PROD1-A represents a vNet operating in „access mode‟ for external VLAN
1.
� VC Uplink 2 is assigned to a Shared Uplink Set (SUS) and is tagged with VLANs 2 thru 4.
� The external switch port is a trunk port carrying VLANs 2 thru 4
� VLAN 2 is represented by vNet-PROD2-A
� VLAN 3 is represented by vNet-PROD3
� VLAN 4 is represented by vNet-PROD4
� VC Uplink 3 is assigned to vNet_ESX and is operating in 802.1Q tunneling mode.
� The external switch port is a trunk port carrying VLANs 1 thru 3.
� vNet_ESX is a single vNet that represents VLANs 1 thru 3.
� pNIC 2 on Servers 3 and 16 have VLAN tagging configured on the server carrying VLANs
1 thru 3.
� pNIC 1 on Server 2 has VLAN tagging configured on the server carrying VLANs 1 and 2.
� All other NICs are not using VLAN tagging. All of these NICs are connected to a single
VLAN (see color for VLAN association).
� NIC 1 on Server 1 can talk directly to NIC 1 on Server 2 without leaving the VC Domain.
� In order for NIC 1 on Server 1 to talk to NIC 2 on Server 3, the frames must first exit the
VC Domain via VC uplink 1, transit the external switch on VLAN 1, and then re-enter
the VC Domain on VC uplink 3.