HP Virtual Connect for c-Class BladeSystem Setup and Installation Guide

Installation 40
In this case, the Ethernet packets are passed unchanged between the server blades and the external
networks. Any VLAN tags added by the server or external switch are ignored and pass through the VC-Enet
modules.
The previous figure also shows a local connection between Server Blade 2 and Server Blade 16, which might
be used in a cluster or as a network heartbeat.
Mapping a single network to multiple uplinks (uplink port set)
A single network can be mapped to more than one external uplink port to provide improved throughput and
availability, referred to as an uplink port set. Review the following guidelines before mapping a single
network to an uplink port set:
• External uplink ports within an uplink port set can be on the same VC-Enet module or on multiple VC-Enet
modules within the Virtual Connect domain.
• Cables can be connected to one or more data center Ethernet switches.
• When multiple external uplink ports are used for the same network, the VC-Enet modules provide
automatic loop prevention by enabling for a single active link or link set at any one time.
• VC automatically chooses the uplink port that optimizes throughput and availability. Where possible,
links within the uplink port set automatically form a link aggregation group with LACP. This action
requires multiple uplink ports on a single VC-Enet module to be connected to an external switch that is
capable and configured to form link aggregation groups with LACP.
In the following example, a single network is mapped to four external uplink ports.
Network Uplink port set
Production_Network
{ Enclosure1:Bay1:Port1
Enclosure1:Bay1:Port2
Enclosure1:Bay2:Port1
Enclosure1:Bay2:Port2 }
In this example, the ports from Bay 1 could be connected to one external switch, and the ports on Bay 2 could
be connected to a second switch. If the external switches support link aggregation, then this configuration
would provide an active 2-Gb link to one switch and a standby 2-Gb link to the other.