Cisco SFE2000 Release Note page 11

1 February 2007
Full 802.1Q VLAN Tagging Compliance
IEEE 802.1Q defines an architecture for virtual bridged LANs, the services provided in VLANs and the
protocols and algorithms involved in the provision of these services.
Protocol Based VLAN
VLAN classification rules are defined on data-link layer (Layer 2) protocol identification. Protocol based
VLANs are used for isolating Layer 2 traffic for differing Layer 3 protocols.
GVRP Support
GARP VLAN Registration Protocol (GVRP) provides IEEE 802.1Q-compliant VLAN pruning and
dynamic VLAN creation on 802.1Q trunk ports. When GVRP is enabled, the device registers and
propagates VLAN membership on all ports that are part of the active underlying "Spanning Tree
Protocol Features" topology.
Private VLAN Edge
A port can be defined as a Private VLAN Edge port of an uplink port, so that it will be isolated from
other ports.
Spanning Tree Protocol Features
Spanning Tree Protocol (STP)
802.1d Spanning tree is a standard Layer 2 switch requirement that allows bridges to automatically
prevent and resolve L2 forwarding loops. Switches exchange configuration messages using specifically
formatted frames and selectively enable and disable forwarding on ports.
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 devices 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.
IEEE 802.1w Rapid Spanning Tree
Spanning Tree can take 30-60 seconds for each host to decide whether its ports are actively forwarding
traffic. Rapid Spanning Tree (RSTP) detects uses of network topologies to enable faster convergence,
without creating forwarding loops.
IEEE 802.1s Multiple Spanning Tree
Multiple Spanning Tree (MSTP) operation maps VLANs into STP instances. MSTP provides differing
load balancing scenario. Packets assigned to various VLANs are transmitted along different paths within
MSTP Regions (MST Regions). Regions are one or more MSTP bridges by which frames can be
transmitted. The standard lets administrators assign VLAN traffic to unique paths.
Linksys One Ready Communications Solution SFE2000/
SFE2000P and SGE2000/SGE2000P
RELEASE NOTES
Linksys One Ready Communications Solution
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