H3C Technologies H3C WX5500E Series Access Controllers - Manual (Page 20)

9
Step Command Remarks
5. Set the unknown unicast
suppression threshold ratio.
unicast-suppression { ratio | pps
max-pps | kbps max-kbps }
Optional.
By default, unknown unicast traffic
is allowed to pass through an
interface.
Enabling loopback detection on an Ethernet interface
If a device receives a packet that it sent, a loop has occurred to the device. Loops might cause broadcast
storms, which degrade network performance. You can use this feature to detect whether a loop has
occurred.
Depending on whether the receiving interface is the same as the sending interface, loops fall into the
following types:
• Single-port loopback—Single-port loopback occurs when an interface receives a packet that it sent
and the receiving interface is the same as the sending interface, as shown in Figure 3 .
• Multi-port loopback—Multi-port loopback occurs when a device receives a packet that it sent but
the receiving interface might not be the sending interface, as shown in
Figure 4 .
Figure 3 Single-port loopback
Figure 4 Multi-port loopback
You can enable loopback detection to detect loops on an interface and, if the interface supports the
loopback-detection action command, configure the protective action to take on the receiving interface
when a loop is detected, for example, to shut down the interface. Depending on whether a protective
action is configured, the device takes the actions in Table 1 to alleviate the impact of the loop condition.