HP Virtual Connect 1Gb Ethernet Cookbook

vNets, Tunnels and Shared Uplink Sets
vNet
There are two types of vNets. The first is a simple vNet that will pass only untagged frames. The second is a vNet
tunnel which will pass tagged frames for one or many VLANs.
The vNet is a simple network connection between one or many server NICs to one or many uplink ports.
A vNet could be used to connect a single VLAN, no tagging, to one or many server NICs, if this network is part of a
VLAN, by configuring the upstream switch port as an access or untagged port, by extension, any server connected
to this vNet would reside in that VLAN, but would not need to be configured to interpret the VLAN tags.
Benefits of a vNet
A vNet can be setup to provide connectivity without the need to configure VLANs within VC.
vNet Tunnel
A tunneled vNet will pass VLAN tagged frames, without the need to interpret or forward those frames based on
the VLAN tag. Within a tunneled vNet the VLAN tag is completely ignored by Virtual Connect and the frame is
forwarded to the appropriate connection (server NIC[s] or uplinks) depending on frame direction flow. In this
case, the end server would need to be configured to interpret the VLAN tags. This could be a server with a local
operating system, in which the network stack would need to be configured to understand which VLAN the server
was in, or a virtualization host with a vSwitch supporting multiple VLANs.
The tunneled vNet can support up to 4096 VLANs.
Benefits of a vNet Tunnel
A vNet tunnel can present one or many VLANs to a server NIC. When additional VLANs are added to the upstream
switch port, they are made available to all server NICs connected to the VLAN Tunnel, with no changes required
within Virtual Connect. All presented VLANs are passed through the tunnel, unchanged. A vNet Tunnel can pass
an unlimited number of VLANs (4096) and is not constrained by the VLAN limits of the Shared Uplink Set.
Shared Uplink Set (SUS)
The SUS provides the ability to support VLAN tagging and forward frames based on the VLAN tags of those
frames. The SUS connects one or many server NICs to one or many uplink ports. A SUS would be configured for
the specific VLANs it will support. If support for additional VLANs is required, those VLANs need to be configured
within the SUS.
When connecting a server NIC to a network within a SUS, there are two choices provided. The key difference
between these two options is the state in which the frame is passed to the server NIC. When configuring a server
NIC for network connection;
1. Selecting a single network – which would be mapped to a specific VLAN.
If a single network is selected, the frames will be presented to the server NIC WITHOUT a VLAN tag. In
this case the host operating system does not need to understand which VLAN it resides in. When the
server transmits frames back to VC, those frames will not be tagged, however; Virtual Connect will add
the VLAN tag and forward the frame onto the correct VLAN.
2. Selecting multiple networks – which would provide connectivity to one or more VLANs.
The Map VLAN Tags feature provides the ability to use a Shared Uplink Set to present multiple networks
to a single NIC. If you select Multiple Networks when assigning a Network to a server NIC, you will have
the ability to configure multiple Networks (VLANS) on that server NIC. At this point VC tags ALL the
packets presented to the NIC — unless the Native check box is selected for one of the networks, in which
case packets from this network (VLAN) will be untagged, and any untagged packets leaving the server
will be placed on this Network (VLAN).