Avaya C360 Manager, Руководство по установке и настройке

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Spanning Tree Protocol
Issue 2 July 2005 133
RSTP provides a means of fast network convergence after a topology change. It does this by
assigning different treatments to different port types. The port types and the treatment they
receive follow:
●
Edge ports - Setting a port to "edge-port" admin state indicates that this port is connected
directly to end stations that cannot create bridging loops in the network. These ports
transition quickly to forwarding state. However, if BPDUs are received on an Edge port, it's
operational state will be changed to "non-edge-port" and bridging loops will be avoided by
the RSTP algorithm. The default admin state of all ports is "edge-port".
Note:
Note:
You must manually configure uplink and backbone ports (including LAG logical
ports) to be "non-edge" ports, using the CLI command
set port edge admin
state
.
●
Point-to-point Link ports - This port type applies only to ports interconnecting RSTP
compliant switches and is used to define whether the devices are interconnected using
shared Ethernet segment or point-to-point Ethernet link. RSTP convergence is faster when
switches are connected using point-to-point links. The default setting for all ports -
automatic detection of point-to-point link - is sufficient for most networks.
Spanning Tree Implementation in the C360
RSTP is implemented in C360 family of products so that it is interoperable with the existing
implementation of STP. In order to configure the switch to either common Spanning Tree or
Rapid Spanning Tree protocol, use the
set spantree version
command.
The balance of this section lists the conditions and limitations that govern the implementation of
Spanning Tree in the C360 family.
●
RSTP's fast convergence benefits are lost when interacting with legacy (STP) bridges.
●
When RSTP detects STP Bridge Protocol Data Units (BPDUs type 1) on a specific port, it
will begin to "speak" 802.1d on this port only. Specifically, this means:
- 802.1d bridges will ignore RSTP BPDUs and drop them.
- 802.1d bridges will send 802.1d format BPDUs back to the switch.
- The switch will change to 802.1d mode for that port only .
The C360 configured to RSTP is therefore able to simultaneously work with other switches
implementing either RSTP or STP without specific user intervention.
●
Spanning Tree configuration is performed on the stack level.
●
RSTP is interoperable with C360 Port Redundancy and 802.1x applications. If either
RSTP or 802.1x put the port in blocking, its final state will be "blocking".
●
You must manually configure uplink and backbone ports to be "non-edge" ports for both
STP and RST using the
set port edge admin state
CLI command.