ZyXEL Communications ONU-2024 Series, User Manual

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Chapter 22 Loop Guard
ONU User’s Guide
171
Figure 89 Loop Guard - Probe Packet
The ONU also shuts down port N if the probe packet returns to switch A on any other port. In
other words loop guard also protects against standard network loops. The following figure
illustrates three switches forming a loop. A sample path of the loop guard probe packet is also
shown. In this example, the probe packet is sent from port
N and returns on another port. As
long as loop guard is enabled on port N . The ONU will shut down port N if it detects that the
probe packet has returned to the ONU.
Figure 90 Loop Guard - Network Loop
"
After resolving the loop problem on your network you can re-activate the
disabled port (see
Section 7.7 on page 74 ).
A
B
P
P
N
A
P
P
N
P