Specifications

HP Virtual Connect for Cisco Network Administrators (version 1.2x) page 19
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 a sample configuration showing VC uplinks connected to a Cisco switch configured for VLAN
trunking, see the section below entitled “Sample Virtual Connect Ethernet and Cisco
Configurations”. The Cisco switch commands are the same for VC in VLAN Trunking mode or VC in
VLAN Tunneling mode.
Unsupported Cisco VLAN Protocols
There are two proprietary Cisco VLAN protocols that Virtual Connect does not support – VTP and
DTP.
VTP, or VLAN Trunking Protocol, is a Cisco proprietary protocol used to manage a single VLAN
database across multiple switches within the same domain. Since VC is not a Cisco device, VC
does not support VTP. As such, there is no possibility that an improperly configured VC Domain can
cause harm to the VTP Domain. Since VC does not support VTP, an administrator is required to add
every VLAN that needs to be trunked on a VC uplink port.
DTP, or Dynamic Trunking Protocol, is a Cisco proprietary protocol used for automating the VLAN
trunking configuration between a pair of directly connected Cisco ports. With DTP enabled, one
Cisco switch port can be configured for VLAN trunking and the partner switch port can
automatically configure its VLAN trunking configuration to match. Since VC is not a Cisco device,
VC does not support DTP. HP recommends that the Administrator disable DTP on the directly
connected Cisco switch ports using the command “switchport nonegotiate”.
Virtual Connect and NIC Teaming
Virtual Connect supports NIC Teaming (or NIC bonding) on server NIC ports. For Windows on x86, VC
supports Network Fault Tolerance (NFT) and Transmit Load Balancing (TLB) but does not support
Switch-assisted Load Balancing (SLB). For Windows on Integrity, VC supports Network Fault Tolerance
(NFT), Transmit Load Balancing (TLB), and static Dual Channel with only two NIC ports in the team,
but does not support Switch-assisted Load Balancing (SLB). For Linux, VC supports any NIC bonding
type that does not require 802.3ad (static or dynamic using LACP) on the server NIC ports.
Virtual Connect also supports a feature called “SmartLink” that is enabled on vNets used by servers
with NIC Teaming\bonding enabled. The SmartLink feature will disable the VC downlinks (server NIC
ports) whenever all the VC uplinks for the associated vNet are unplugged. Basically, the SmartLink
feature propagates a link-down event of a vNet’s uplinks to the server NICs in the team. This allows
the NIC Teaming software to failover from one vNet (with all failed uplinks) to another vNet with
functional uplinks. SmartLink is only used in NIC Teaming configurations when the NIC ports in the
Team are connected to different vNets (see “Figure 12. VC Domain Showing Advanced Usage of