Nortel BayStack 5520-48T-PWR Install Manual

Also see for BayStack 5520-48T-PWR: Configuration Specifications Product brief

Contents

34 Installation fundamentalsDuring the initial installation of the stack, the software automaticallydetermines the physical order of all units in the stack according to theposition of the base unit within the stack. Thereafter, the individual unitsmaintain their original unit numbering, even if the position of one or moreunits in the stack is changed.For example, when the stack is initially powered, the base unit becomesunit 1 and the unit that the base unit connects to (via the Cascade Downcable) becomes unit 2 (and the next unit is unit 3 and so on), until themaximum stack configuration (up to 8 units for a 5500 Series stack or ahybrid stack; up to 8 units for a pure 5600 Series stack) is reached. If thebase unit is changed to another unit in the stack, the new base unit keepsits original unit number in the stack.When a switch participates in a stack configuration, a stack MAC addressis automatically assigned during stack initialization. The stack MACaddress is the base unit MAC address plus 1. If another unit in the stackis assigned as the base unit, the new stack MAC address is the MACaddress of the new base unit plus 1. The original stack IP address stillapplies to the new base unit.If an assigned base unit fails, the next unit in the stack order automaticallybecomes the new temporary base unit. This change is indicated by theBase LED on the temporary base unit LED display panel moving to asteady amber state.This automatic failover is a temporary safeguard only. If the stackconfiguration loses power, the temporary base unit will not power up asthe base unit when power is restored. Also, if the original unit rejoins thestack, it will not resume base unit status. For this reason, always assignthe temporary base unit as the base unit until the failed unit is repairedor replaced.Attention: If the temporary base unit is not assigned as the new baseunit, and the temporary base unit fails, the next unit in the stack orderbecomes the temporary base unit. This process will continue aftersuccessive failures until only two units are left in the stack.Regardless of stack configuration, the following applies:ERS 5000 Series InstallationNN47200-300 04.0313 April 2009Copyright © 2008–2009 Nortel Networks