set spb basevid

Use this command to configure an ECT algorithm and shortest path VID to a Base-VID.

Syntax

Parameters

Defaults

• The symmetric ECT algorithm defaults to 1.
• The SPVID defaults to 0 (unassigned).

Mode

All command modes.

Usage

It is likely that there will be more than one shortest path between two SPB bridges. The VLAN shortest path bridging mode (SPBV) supports Equal Cost Multiple Paths (ECMP). Commonly defined Equal Cost Tree (ECT) algorithms are used to select a path among available equal cost paths. The IEEE 802.1Qaq standard defines 16 ECT algorithms.

A single ECT algorithm is assigned to a Base-VID. The combination of Base-VID and configured ECT algorithm is used to make forwarding decisions. If you do not specify the ECT algorithm when entering this command, the ECT algorithm defaults to 1.

The IS-IS Hello PDU carries the mapping between the Base-VID and the ECT algorithm between SPB adjacencies. Information transmitted in the IS-IS Hello PDU ensures that the adjacent SPB bridges use the same ECT algorithm for a given Base-VID. An SPB adjacency is not formed if the mapping does not agree.

Each ECT is assigned a unique shortest path VID (SPVID) for the Base-VID. The ECT to shortest path VID mapping can be administratively assigned using this command. To administratively assign the SPVID, SPB mode must be set to manual using set spb system. VLAN mode defaults to auto. When in auto mode, SPVIDs are dynamically assigned. Regardless of the SPB VLAN mode configured, SPVIDs are reserved in a VLAN pool configured using set spb spvid.