Static link aggregation 29Spanning Tree Protocol topology change detectionChange detection enables the detection of topology changes and sends atopology change notification (TCN) to the Root, on an individual port basis.Change detection is enabled by default. When change detection is enabledand a topology change occurs, a trap is sent containing the followinginformation so that you can identify the device:• the MAC address of the STG sending the TCN• the port number• the STG IDYou can disable change detection on ports where a single end station isconnected, and where powering that end station on and off triggers theTCN. Change detection is referenced in IEEE STD 802.1D.Topology change detection configuration rulesThe following rules apply to the Spanning Tree topology change detectionsetting.Table 4Spanning Tree Protocol topology change detection configuration rules• You can configure change detection on access ports only. This also applies to link aggregationports.• If you disable change detection and then change the port from access to tagging-enabled,the switch automatically sets change-detection to enabled for the port. This also applies tolink aggregation ports.• In a link aggregation group with access ports, modifications to change detection for a memberport are automatically applied to the remaining member ports.Static link aggregationLink aggregation is a point-to-point connection that aggregates multipleports so that they logically act like a single port with the aggregatedbandwidth. Grouping multiple ports into a logical link provides higheraggregate throughput on a switch-to-switch or switch-to-server application.Link aggregation provides media and module redundancy.The ERS 8300 supports link aggregation in a static configuration modewhere no LACP is used. The ERS 8300 link aggregation is interoperablewith Baystack and Ethernet Routing Switch 8600 link aggregation, alsoreferred to as MLT.This section includes the following topics:• "Link aggregation traffic distribution" (page 30)• "Link aggregation rules" (page 30)• "Link aggregation examples" (page 31)Nortel Ethernet Routing Switch 8300Configuration — VLANs, Spanning Tree, and Static Link Aggregation using Device ManagerNN46200-510 03.01 Standard4.0 27 August 2007Copyright © 2005-2007, Nortel Networks.
