GS2210 Series User’s Guide
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H A P T E R
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ZULD
37.1 ZULD Overview
A unidir ect ional link is a connect ion w her e t he link is up on bot h ends, but only one end can r eceive
packet s. This m ay happen if OAM was init ially enabled but t hen disabled, t her e ar e m isconfigur ed
t ransm it t ing or r eceiving lines or t he har dwar e is m alfunct ioning. Zy XEL Unidir ect ional Link
Det ect ion ( ZULD ) is a layer - 2 pr ot ocol t hat can det ect and disable t hese physical one- way links
befor e t hey cause loops or com m unicat ion m alfunct ion.
I n t he figur e below, S1 - A is a bidir ect ional link as bot h ends can send packet s t o each ot her. S1- B
is unidir ect ional as B cannot send packet s t o S1 ( alt hough t he S1- B link is up) . Sim ilar ly, S2- S1 is
unidir ect ional as S1 cannot send packet s t o S2 ( alt hough t he S1- S2 link is up) .
Figure 224
ZULD Over view
37.1.1 What You Can Do
•
Use t he ZULD St a t u s scr een (
) t o see det ails on ZULD.
•
Use t he ZULD Con figu r a t ion scr een (
) t o enable ZULD on a por t ,
configure a m ode and set t he probe t im e.
37.1.2 What You Need to Know
•
ZULD m ust be enabled on t he Swit ch and t he por t( s) in or der t o det ect unidir ect ional links by
m onit or ing OAMPDUs.
