Chapter 61 Error-Disable
GS1920v2 Series User’s Guide
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CHAPTER 61
Error-Disable
61.1  Error-Disable Overview
This chapter shows you how to configure the rate limit for control packets on a port, and set the Switch 
to take an action (such as to shut down a port or stop sending packets) on a port when the Switch 
detects a pre-configured error. It also shows you how to configure the Switch to automatically undo the 
action after the error is gone.
61.1.1  CPU Protection Overview
Switches exchange protocol control packets in a network to get the latest networking information. If a 
switch receives large numbers of control packets, such as ARP, BPDU or IGMP packets, which are to be 
processed by the CPU, the CPU may become overloaded and be unable to handle regular tasks 
properly.
The CPU protection feature allows you to limit the rate of ARP, BPDU and IGMP packets to be delivered 
to the CPU on a port. This enhances the CPU efficiency and protects against potential DoS attacks or 
errors from other networks. You then can choose to drop control packets that exceed the specified rate 
limit or disable a port on which the packets are received.
61.1.2  Error-Disable Recovery Overview
Some features, such as loop guard or CPU protection, allow the Switch to shut down a port or discard 
specific packets on a port when an error is detected on the port. For example, if the Switch detects that 
packets sent out the ports loop back to the Switch, the Switch can shut down the ports automatically. 
After that, you need to enable the ports or allow the packets on a port manually through the Web 
Configurator or the commands. With error-disable recovery, you can set the disabled ports to become 
active or start receiving the packets again after the time interval you specify.
61.1.3  What You Can Do
• Use the Errdisable Status screen (Section 61.2 on page 381) to view whether the Switch detected that 
control packets exceeded the rate limit configured for a port or a port is disabled according to the 
feature requirements and what action you configure, and related information.
• Use the CPU Protection screen (Section 61.3 on page 382) to limit the maximum number of control 
packets (ARP, BPDU and/or IGMP) that the Switch can receive or transmit on a port.
• Use the Errdisable Detect screen (Section 61.4 on page 383) to have the Switch detect whether the 
control packets exceed the rate limit configured for a port and configure the action to take once the 
limit is exceeded.
• Use the Errdisable Recovery screen (Section 61.5 on page 384) to set the Switch to automatically 
undo an action after the error is gone.