Internet Group Management Protocol; Data Storm Prevention; Quality Of Service - HP BladeSystem bc2000 - Blade PC Installation Manual

an "Aggregated Link" may be of different media types (UTP/Fiber, or different fiber types), provided they
are of the same speed and duplex.
Aggregated Links may be set up manually, or automatically by enabling LACP (Link Aggregation Control
Protocol) on the relevant links. An Aggregated Link is treated by the system as a single logical port, in
the same manner as any other port in the system. In particular, the Aggregated link has port attributes
similar to a "regular" port – Auto negotiation state, speed, etc.
Each switch supports up to eight multi-port trunks with up to eight ports per trunk.

Internet Group Management Protocol

By default, a Layer 2 switch forwards multicast frames to all ports of the relevant VLAN, treating the
frame as if it were a broadcast. The result is that some ports may receive irrelevant frames only needed
by a subset of the ports of that VLAN.
This may be alleviated by explicit system configuration, or by "snooping" (examining the contents of)
IGMP frames as they are forwarded by the switch from stations to an upstream multicast router. This
allows a switch to conclude the following:
●
Where (on which ports) stations interested in joining a specific multicast group are located
●
Where (on which ports) multicast routers sending multicast frames are located
This knowledge may be used to exclude irrelevant ports (ports on which no stations have registered to
receive a specific multicast group) from the forwarding set of an incoming multicast frame.
The switch provides Internet Group Management Protocol (IGMP) snooping v1 and v2, configurable to
a non-querier mode. The IGMP state may be enabled and disabled on a per VLAN basis as well as a
configurable response report delay and query interval. Each switch allows a maximum of 191 concurrent
multicast groups (127 dynamically learned by IGMP, 64 static Multicast).

Data Storm Prevention

When L2 frames are forwarded, broadcast and multicast frames are flooded to all ports on the relevant
VLAN. Moreover, all nodes connected to these ports will accept and try to process these frames, placing
load on both the network links and the host operating systems (as each of these frames creates at least
an I/O interrupt, if only to decide that it is to be discarded).
The switch permits configurable thresholds (in packets per second) to prevent three types of packet
storms: broadcast, Multicast, and destination address unknown. If the threshold is exceeded, any
additional packets received would be dropped.

Quality of Service

The system enables various services for specific traffic flows to be defined. This is achieved by two
mechanisms:
●
Classification — Certain fields are specified within the packet, which are matched to some values.
All packets matching those fields are related to the same flow/class.
●
Actions — Various actions can be set, such as manipulating fields within the packet (for example,
VPT, DSCP), policing at the ingress, scheduling at the egress, and shaping at the egress. Same
actions are applied to all packets within a specific flow.
The mechanism for supporting these actions related to bandwidth management and control is the
concept of queues. After a packet has been classified it is assigned to one of the output queues. The
ENWW Switch Serviceability 9