Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 476)

446 Multi-Service IronWare Switching Configuration Guide
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RSTP support for PB and PBB
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• RSTP interoperability between Brocade MLX series and Brocade NetIron CER devices is not
supported if both are acting as a BEB.
• Running RSTP on a VPLS Instance will not avoid the pure Layer 2 forwarding loop created by
the regular B-VLAN in the BEBs. Run RSTP on regular B-VLAN in BEBs.
• Switchover and hitless upgrade are not supported on PBB RSTP.
• When changing the RSTP parameters on a regular B-VLAN, the parameters also need to be
changed on the VPLS instance. The expectation is to have the same port states for B-VLAN
(regular) end points and VPLS ISID end points.
Configuration commands
Use the following commands to configure RSTP on a PBB VPLS instance.
Syntax: [no] rstp [forward-delay value] | [hello-time value] | [max-age time] | [force-version value]
| [priority value]
The forward-delay parameter specifies how long a port waits before it forwards an RST.
The hello-time parameter specifies the interval between two hello packets. The values range from 1
to 10 seconds. The default is 2 seconds.
The max-age parameter specifies the amount of time the device waits to receive a hello packet
before it initiates a topology change. Acceptable values range from 6 to 40 seconds. The default is
20 seconds. The value of max-age must be greater than the value of forward-delay to ensure that
the downstream bridges do not age out faster than the upstream bridges.
The force-version parameter forces the bridge to send BPDUs in a specific format. You can specify
either of the following values:
0 - The STP compatibility mode. Only STP (or legacy) BPDUs will be sent.
2 - The default. RST BPDUs will be sent unless a legacy bridge is detected. If a legacy bridge is
detected, STP BPDUs will be sent instead.
The priority parameter specifies the priority of the bridge. You can enter a value from 0 to 65535. A
lower numerical value means a the bridge has a higher priority. Thus, the highest priority is 0. The
default is 32768.
The [no] version disables the feature and returns settings to default.
Syntax: [no] rstp ethernet slot/portnum path-cost value | priority value | [admin-edge-port]|
[admin-pt2pt-mac] | [force-migration-check]
The ethernet slot/portnum parameter specifies the interface used.
The path-cost parameter specifies the cost of the port's path to the root bridge. RSTP prefers the
path with the lowest cost. You can specify a value from 1 to 20,000,000.
The priority value parameter specifies the preference that RSTP gives to this port relative to other
ports for forwarding traffic out of the topology. You can specify a value from 0 to 240, in increments
of 16. If you enter a value that is not divisible by four, the software rounds to the nearest value that
is divisible by four. The default is 128. A higher numerical value means a lower priority; thus, the
highest priority is 8.
Set the admin-edge-port to enabled or disabled. If set to enabled, then the port becomes an edge
port in the domain.