Fujitsu Siemens Computers PRIMERGY BX, Description

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Features of the Switch Introduction
Lan Switch and Router Blade
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2.1.3 Spanning Tree Protocol Features
Spanning Tree Protocol (STP)
Spanning Tree Protocol (STP, IEEE 802.1D) – This protocol adds a level of fault
tolerance by allowing two or more redundant connections to be created between a
pair of LAN segments. When there are multiple physical paths between segments,
this protocol will choose a single path and disable all others to ensure that only one
route exists between any two stations on the network. This prevents the creation of
network loops. However, if the chosen path should fail for any reason, an alternate
path will be activated to maintain the connection.
IEEE 802.1w Rapid Spanning Tree
Rapid Spanning Tree Protocol (RSTP, IEEE 802.1w) – This protocol reduces the
convergence time for network topology changes to about 10% of that required by the
older IEEE 802.1D STP standard. It is intended as a complete replacement for STP,
but can still interoperate with switches running the older standard by automatically
reconfiguring ports to STP-compliant mode if they detect STP protocol messages
from attached devices.
IEEE 802.1s Multiple Spanning Tree
IEEE 802.1s Multiple Spanning Tree - The IEEE 802.1s is the supplement to IEEE Std 802.1Q
adds the facility for VLAN bridges to use multiple spanning trees, providing for traffic belonging
to different VLANs to flow over potentially different paths within the virtual bridged LAN.802.1s
supports spanning tree by per VLAN.
Fast Link
STP can take up to 30-60 seconds to converge. During this time, STP detects possible loops,
allowing time for status changes to propagate and for relevant Ethernet Switch Modules to
respond. 30-60 seconds is considered too long of a response time for many applications. The
Fast Link option bypasses this delay, and can be used in network topologies where forwarding
loops do not occur.
Link Aggregation
One Aggregated Links may be defined, with up to 2 member ports, to form a single Link
Aggregated Group (LAG). This enables:
• Fault tolerance protection from physical link disruption
• Higher bandwidth connections
• Improved bandwidth granularity
• High bandwidth server connectivity
LAG is composed of ports with the same speed, set to full-duplex operation.
Link Aggregation and LACP
LACP uses peer exchanges across links to determine, on an ongoing basis, the aggregation
capability of various links, and continuously provides the maximum level of aggregation
capability achievable between a given pair of systems. LACP automatically determines,
configures, binds and monitors the port binding to aggregators within the system.
BootP and DHCP Clients
DHCP enables additional setup parameters to be received from a network server upon system
startup. DHCP service is an on-going process. DHCP is an extension to BootP. For more
information on DHCP, see "Defining DHCP IP Interface Parameters".