54 VLANs, Spanning Tree, and Static Link Aggregation• The SLPP-PDU packet transmission interval is configurable from 500to 5000 milliseconds (ms). The default packet transmission intervalis 500 ms.• After an SLPP-PDU is received on a port that is a member of a multilinktrunk, port members with SLPP-RX enabled and RX-Threshold reached,are disabled.• The SLPP-PDU can be received by the originating CP or the peer SMLTCP. All other switches treat the SLPP-PDU as a normal multicast packet.The switches ignore it and forward it to the VLAN.• SLPP-PDU transmission and reception operates only on ports for whichSTP is in a forwarding state (if STP is enabled on one switch in the path).• You must enable SLPP packet receive on an individual port basis todetect a loop:— SLPP packet reception can only be enabled on SMLT access portsand never on SMLT IST ports or any SMLT square or full meshcore ports.— Vary the SLPP packet receive threshold between the two core SMLTswitches so that if a loop is detected, the access ports on bothswitches do not go down, avoiding SMLT client isolation.• SLPP is port-based, so a port is disabled if it receives SLPP-PDUs onone or more VLANs on a tagged port. For example, if the SLPP packetreceive threshold is set to five, a port is shut down if it receives fiveSLPP-PDUs from one or more VLANs on a tagged port.• SLPP does not have any hardware requirements or dependencies.• SLPP does not support jumbo frames on the ERS 8300 v4.0.• SLPP does not replace the functionality of Spanning Tree Protocol,but is a supplement to help detect and prevent loops in the SMLTenvironment. Nortel recommends that you use this feature in an SMLTenvironment only.• The ERS 8300 Series does not support the use of SLPP in anLACP-SMLT environment.For information about configuring Simple Loop Prevention Protocol, see"Configuring Simple Loop Prevention Protocol" (page 103).Port auto recoveryThe port auto recovery feature can automatically enable a port shut downby SLPP, CP-Limit or Link Flap Detect. When a port with auto recoveryenabled is operationally shut down by SLPP, CP-Limit, or Link Flap Detect,the port is enabled within a specific, configurable time delay.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.
