HP 1.10GB Virtual Connect Ethernet Module for c-Class BladeSystem - Manual (Page 72)

Network management 72
o No server profile connections are assigned to multiple networks not linked to a Shared Uplink
Set.
This action forces all server connections mapped to multiple networks to be linked to a shared uplink
set. Server administrators cannot override this selection when creating or editing a profile.
Multiple Networks Link Speed Settings
When using mapped VLAN tags (multiple networks over a single link), these settings are used for the
overall link speed control. Select the checkbox next to each item to set the value.
These settings affect only newly created profiles. Changing these settings does not affect any assigned
profiles.
To set the speed, click the selection box, select a setting (100Mb to 10Gb), and then click OK.
• Set a Custom value for the Preferred Link Connection Speed.
This value is the default speed for server profile connections mapped to this network. The server
administrator can override this setting on an individual profile connection.
• Set a Custom value for the Maximum Link Connection Speed.
This value is the maximum speed for server profile connections mapped to this network. The server
administrator can override this setting on an individual profile connection.
Virtual Connect can only control link speed for Flex-10 NICs when they are connected to an HP Virtual
Connect Flex-10 Module. Virtual Connect cannot control the link speed of traditional NICs. For additional
information, see "Flex-10 overview (on page 94 )."
MAC Cache Failover
When a VC-Enet uplink that was previously in standby mode becomes active, it can take several minutes
for external Ethernet switches to recognize that the c-Class server blades can now be reached on this
newly-active connection. Enabling Fast MAC Cache Failover causes Virtual Connect to transmit Ethernet
packets on newly-active links, which enables the external Ethernet switches to identify the new connection
(and update their MAC caches appropriately). This transmission sequence repeats a few times at the
MAC refresh interval (5 seconds recommended) and completes in about 1 minute.
IMPORTANT: Be sure to set switches to allow MAC addresses to move from one port to
another without waiting for an expiration period or causing a lock out.
IGMP Snooping
The IGMP Snooping feature allows VC-Enet modules to monitor (snoop) the IGMP IP multicast membership
activities and configure hardware Layer 2 switching behavior of multicast traffic to optimize network
resource usage. Currently only IGMP v1 and v2 (RFC2236) are supported.
The IGMP Snooping idle timeout interval is set to 260 seconds by default. This value is the "Group
Membership Interval" value as specified by IGMP v2 specification (RFC2236). For optimum network
resource usage, set the interval to match the configuration on the customer network's multicast router
settings.