H3C Technologies H3C S12500 Series Switches - Manual (Page 220)

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Configuring MAC-in-MAC
The switch does not support MAC-in-MAC when it operates in standard mode. For more information
about system operating modes, see Fundamentals Configuration Guide.
EC2 cards do not support MAC-in-MAC. EC2 cards refer to the cards ending with EC2.
Overview
MAC-in-MAC, also known as Provider Backbone Bridge (PBB), is defined in IEEE 802.1ah. MAC-in-MAC
is a Layer-2 Virtual Private Network (VPN) technique. It encapsulates the customer MAC in the service
provider MAC, transmits the inner MAC as payload, and thus improves the expandability for Ethernet
and secures services.
Basic concepts
Figure 76 shows a typical MAC-in-MAC network. This section introduces some basic concepts of
MAC-in-MAC based on this network.
Figure 76 A typical MAC-in-MAC network
PBBN
As shown in Figure 76 , a network using MAC-in-MAC is called a provider backbone bridge network
(PBBN) or MAC-in-MAC network. For users, a PBBN is a Layer-2 switching network where Layer-2
connections are between different nodes.
Customer
network
Customer
network
Customer
network
Customer
network
Customer
network
Customer
network
PBBN
PBN PBN
BCB BCB
BCB BCB
BEB BEB
BEB BEB