Amer Networks SS3GR24i - Manual (Page 28)

SS3GR24i/SS3GR48i Layer3 Stackable Gigabit Switch User’s Guide
• Filtering done for VLAN integrity. Packets from a
member of a VLAN (VLAN 2, for example) destined for a
device on another VLAN (VLAN 3) will be filtered.
Some filtering requires the manual entry of information into a
filtering table:
• MAC address filtering – the manual entry of specific
MAC addresses to be filtered from the network. Packets
sent from one manually entered MAC address can be
filtered from the network. The entry may be specified as
either a source, a destination, or both.
802.1w Rapid Spanning Tree
The Switch implements two versions of the Spanning Tree
Protocol, the Rapid Spanning Tree Protocol (RSTP) as defined by
the IEEE 802.1w specification and a version compatible with the
IEEE 802.1d STP. RSTP can operate with legacy equipment
implementing IEEE 802.1d, however the advantages of using
RSTP will be lost.
The IEEE 802.1w Rapid Spanning Tree Protocol (RSTP) evolved
from the 802.1d STP standard. RSTP was developed in order to
overcome some limitations of STP that impede the function of some
recent switching innovations, in particular, certain Layer 3
functions that are increasingly handled by Ethernet switches. The
basic functions and much of the terminology is the same as STP.
Most of the settings configured for STP are also used for RSTP.
This section introduces some new Spanning Tree concepts and
illustrates the main differences between the two protocols.
Port Transition States
An essential difference between the two protocols is in the way
ports transition to a forwarding state and in the way this
transition relates to the role of the port (forwarding or not
forwarding) in the topology. RSTP combines the transition states
disabled , blocking and listening used in 802.1d and creates a single
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