Fan Failure; Mitigating Flapping Transceivers - HP Aruba JL253A Management And Configuration Manual

The information is retained in the config file to allow you to boot up the switch and have it function as it did
when it was configured with earlier software that allows overlapping subnets.If you attempt to remove the
overlapping subnet from the VLAN, the switch displays an error message similar to:
The IP address <ip-address> is not configured on this VLAN
This occurs because the overlapping IP address has been removed and is not visible to the switch. To resolve
this:
• Enter the show ip command to determine which addresses are visible to the switch.
• Remove the erroneous IP addresses from the config file by entering the no ip address command to
remove all the IP addresses from the specific VLAN. Be sure to document the other valid IP addresses on that
VLAN so they can be restored after removing the erroneous IP addresses from the config file.
If you go back to a software version prior to WB.15.09 before removing the overlapping IP address, the prior
software version enables the overlapping IP subnet.

Fan failure

Whenever a fan failure occurs, the Fan/Fault LEDs blink amber and a log entry is recorded. During a fan failure,
all operational fans are automatically set to the maximum operating speed until the fan failure has been resolved.
At that time, the fan speed is reset to the minimum operating speed.

Mitigating flapping transceivers

In traditional switches, the state of a link is driven directly by the reported state of the port, which is required for
rapid detection of link faults. However, the consequence of this is that a marginal transceiver, optical, or wire
cabling, one that "flaps" up and down several times per second, can cause STP and other protocols to react
poorly, resulting in a network outage. The link-flap option expands the functionality of the existing fault finder
function to include a "link-flap" event and a new action of "warn-and-disable." Together, these additions allow the
errant condition to be detected, and the port in question can be optionally disabled.
Syntax:
fault-finder <link-flap> sensitivity {<low | medium | high} > action {<warn | warn-and-disable>}
Default settings: Sensitivity = Medium; Action = Warn
Sensitivity thresholds are static. In a 10-second window, if more than the threshold number of link state transitions
(up or down) are detected, the event is triggered. The 10-second window is statically determined, that is, the
counters are reset every 10 seconds, as opposed to being a sliding window. The counters are polled twice per
second (every 500 milliseconds), and the event is triggered if the sensitivity threshold is crossed at that time.
The sensitivity thresholds are:
High
Medium
Low
Configuring the link-flap event and corresponding action applies to all ports and port types (it is a global setting
per FFI event type). Note that normal link transition protocols may prevent link state changes from occurring fast
enough to trigger the event for some port types, configurations, and sensitivity settings.
474
3 transitions in 10 seconds
6 transitions in 10 seconds
10 transitions in 10 seconds
Aruba 2930F / 2930M Management and Configuration Guide
for ArubaOS-Switch 16.08