Access Control | 205Figure 13-166. Loopback ACL ExampleEnabling Broadcast Storm ControlA broadcast storm occurs when incoming packets flood the LAN, degrading network performance. SFTOSprovides broadcast storm control at a global (switch) level, not for individual interfaces.To enable storm control, execute the command storm-control broadcast in Global Config mode. Disablestorm control with the command no storm-control broadcast.Broadcast storm control is implemented in SFTOS with automated high and low thresholds that are basedon a percentage of link speed. If broadcast traffic on any port exceeds the high threshold percentage (asrepresented in the following table) of the link speed, the switch discards the broadcast traffic until thetraffic returns to the low threshold percentage or less.Use the show storm-control command to verify the setting.Use the show interface-ethernet unit/slot/port command to see the number of packets not forwarded(highlighted in Figure 13-167) in a broadcast storm condition when broadcast storm control has beenimplemented.Table 13-7. Broadcast Storm Control ThresholdsLink Speed High Low10M 20 10100M 5 21000M 5 2Force10 (Config)#access-list 2 permit everyForce10 (Config)#access-list 2 deny 10.240.4.113 255.255.255.0Force10 (Config)#interface loopback 0Force10 (Conf-if-lo-0)# ip access-group 2 in 10Force10 (Conf-if-lo-0)# exitForce10 #show ip access-lists 2ACL ID: 2Interface :loopbackRule Number: 1Action......................................... permitMatch All...................................... TRUERule Number: 2Action......................................... denyMatch All...................................... FALSESource IP Address.............................. 10.240.4.113Source IP Mask................................. 255.255.255.0--More-- or (q)uit10 is the priority, an optional parameter.
