Layer 2 Protocol Tunneling; Layer 2 Protocol Tunneling Overview - ZyXEL Communications GS2210-8 User Manual

28.1 Layer 2 Protocol Tunneling Overview

This chapt er shows you how t o configure layer 2 prot ocol t unneling on t he Swit ch.
28.1.1 What You Can Do
Use t he La ye r 2 Pr ot ocol Tu n ne l screen (
t unneling on t he Swit ch and specify a MAC address wit h which t he Swit ch uses t o encapsulat e t he
layer 2 prot ocol packet s by replacing t he dest inat ion MAC address in t he packet s.
28.1.2 What You Need to Know
Layer 2 prot ocol t unneling ( L2PT) is used on t he service provider's edge devices.
L2PT allows edge swit ches ( 1 and 2 in t he following figure) t o t unnel layer 2 STP ( Spanning Tree
Prot ocol) , CDP ( Cisco Discovery Prot ocol) and VTP ( VLAN Trunking Prot ocol) packet s bet ween
cust om er swit ches ( A, B and C in t he following figure) connect ed t hrough t he service provider 's
net work. The edge swit ch encapsulat es layer 2 prot ocol packet s wit h a specific MAC address before
sending t hem across t he service provider 's net work t o ot her edge swit ches.
Figure 183 Layer 2 Prot ocol Tunneling Net work Scenario
A
STP
CDP
VTP
B
I n t he following exam ple, if you enable L2PT for STP , you can have swit ches A, B, C and D in t he
sam e spanning t ree, even t hough swit ch A is not direct ly connect ed t o swit ches B, C and D.
Topology change inform at ion can be propagat ed t hroughout t he service provider 's net work.
To em ulat e a point- t o- point t opology bet ween t wo cust om er swit ches at different sit es, such as A
and B, you can enable prot ocol t unneling on edge swit ches 1 and 2 for PAgP ( Port Aggregat ion
Prot ocol) , LACP or UDLD ( UniDirect ional Link Det ect ion) .
C
HAPTER

Layer 2 Protocol Tunneling

Sect ion 28.2 on page
Service Provider's
Network
STP
1
CDP
VTP
GS2210 Series User's Guide
261
262) t o enable layer 2 prot ocol
C
2
2 8