HP Virtual Connect Manager Command Line Interface for c-Class BladeSystem Version 4.01 User Guide

Configuring the Virtual Connect domain using the CLI 170
The IGMP Snooping feature enables 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. IGMP v1, v2, and v3 snooping 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.
By default, unregistered IGMP multicast traffic traversing VC–Enet modules is flooded on the configured
Ethernet network. To prevent flooding, set the NoFlood property to true.
>set igmp Enabled=true NoFlood=true
Unregistered multicast traffic from uplinks is dropped and traffic from the server ports is redirected to the
active uplink port. IGMP Snooping must be enabled to modify this setting.
For more information about multicast filters, see "mcast-filter (on page 64)."
Configuring MAC cache failover settings
• To configure MAC Cache Failover settings, use the set mac-cache command:
>set mac-cache enabled=true refresh=10
• To display MAC Cache Failover settings, use the show mac-cache command:
>show mac-cache
When a VC-Enet uplink that was previously in standby mode becomes active, external Ethernet switches can
take several minutes 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 (HP
recommends 5 seconds) and completes in about 1 minute.
Virtual Connect only transmits MAC Cache update frames on VLANs that have been configured in the VC
domain. The update frames are VLAN tagged appropriately for networks defined on shared uplink sets. For
dedicated networks, only untagged update frames are generated, regardless of whether or not VLAN
Tunneling is enabled. In a VLAN tunnel, all customer VLAN tags pass through Virtual Connect transparently.
Virtual Connect does not examine nor record VLAN tag information in tunneled networks; therefore, it cannot
generate tagged update frames.
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.
Always enable the "spanning tree portfast" feature to allow the switch port to bypass the
"listening" and "learning" stages of spanning tree and quickly transition to the "forwarding"
stage, allowing edge devices to immediately begin communication on the network.
Configuring network loop protection settings
The loop-protect command is deprecated in 4.01. HP recommends using the port-protect command.
To enable network loop protection, use the set port-protect command:
>set port-protect networkLoop=Enabled
To reset all ports disabled due to the port protection action, use the reset port-protect command:
>reset port-protect