SMC Networks SMC8126L2 Management Manual page 29

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Description of Software Features
Rate Limiting – This feature controls the maximum rate for traffic transmitted or
received on an interface. Rate limiting is configured on interfaces at the edge of a
network to limit traffic into the network. Traffic that falls within the rate limit is
transmitted while packets that exceed the acceptable amount of traffic are dropped.
Port Mirroring – The switch can unobtrusively mirror traffic from any port to a
monitor port. You can then attach a protocol analyzer or RMON probe to this port to
perform traffic analysis and verify connection integrity.
Port Trunking – Ports can be combined into an aggregate connection. Trunks can
be manually set up or dynamically configured using IEEE 802.3ad Link Aggregation
Control Protocol (LACP). The additional ports dramatically increase the throughput
across any connection, and provide redundancy by taking over the load if a port in
the trunk should fail. The switch supports up to 32 trunks.
Broadcast Storm Control – Broadcast suppression prevents broadcast traffic from
overwhelming the network. When enabled on a port, the level of broadcast traffic
passing through the port is restricted. If broadcast traffic rises above a pre-defined
threshold, it will be throttled until the level falls back beneath the threshold.
Static Addresses – A static address can be assigned to a specific interface on this
switch. Static addresses are bound to the assigned interface and will not be moved.
When a static address is seen on another interface, the address will be ignored and
will not be written to the address table. Static addresses can be used to provide
network security by restricting access for a known host to a specific port.
IEEE 802.1D Bridge – The switch supports IEEE 802.1D transparent bridging. The
address table facilitates data switching by learning addresses, and then filtering or
forwarding traffic based on this information. The address table supports up to 8K
addresses.
Store-and-Forward Switching – The switch copies each frame into its memory
before forwarding them to another port. This ensures that all frames are a standard
Ethernet size and have been verified for accuracy with the cyclic redundancy check
(CRC). This prevents bad frames from entering the network and wasting bandwidth.
To avoid dropping frames on congested ports, the SMC8126L2 and SMC8150L2
provide 4 Mbits respectively for frame buffering. This buffer can queue packets
awaiting transmission on congested networks.
Spanning Tree Algorithm – The switch supports these spanning tree protocols:
Spanning Tree Protocol (STP, IEEE 802.1D) – This protocol provides loop detection
and recovery 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.
Rapid Spanning Tree Protocol (RSTP, IEEE 802.1w) – This protocol reduces the
convergence time for network topology changes to 3 to 5 seconds, compared to 30
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