H3C SecPath PFC, Quick Start Manual

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2
How PFC Works
Figure 1 Work mechanism of PFC
As shown in Figure 1 , the PFC interface card (take an 8EPM electrical
interface card for example) has eight interfaces, which are NET A, A, B,
and NET B in each of the two rows. Each row of interfaces protects a
segment.
•
NET A connects to the external network interface.
•
A connects to the interface added to the external zone of the device.
•
B connects to the interface added to the internal zone of the device.
•
NET B connects to the internal network interface.
The traffic direction differs with circumstances:
1. The solid line in Figure 1 shows the traffic direction when the device is
operating correctly. The external traffic enters the device through NET
A, and passes through interface A, the internal zone and external zone
of the device. Then it enters PFC through interface B and then flows to
NET B. Finally, it reaches the internal network.
2. If a power failure, reboot, or interface down occurs on the device, NET
A and NET B are connected directly, and traffic will pass through NET
PFC electrical interface card (8EPM)
(Conne cts the extern al
network in terface)
(Conne cts the
exte rnal zo ne)
(Conne cts the
interna l zone)
(Conne cts the inte rnal
network in terface)
Exte rnal
traffic
Device
(Add ed to the inte rnal zo ne) (Add ed to the externa l zone)
Inte rface C Inte rface D
NET A
A
B
NET B
NET A
A
B
NET B
Inte rnal
traffic