fsUrpfDropRate

The rate of packet drops of IP version fsUrpfIpVersion 
packets due to URPF for the managed device. The 
per-interface drop rate notification is issued on rates 
exceeding a limit (rising rate). This dropping may 
indicate an security attack on the network. To determine 
whether the attack/event is over, the NMS must 
consult the managed device. This object can be polled to 
determine the recent drop rate for the managed device
as a whole, in addition to querying particular interface 
objects.
              
This object is the average rate of dropping over the most 
recent window of time. The rate is computed by dividing 
the number of packets dropped over a window by the window 
time in seconds. The window time is specified by 
fsUrpfDropRateWindow. Each time the drop rate is computed, 
and at system startup, a snapshot is taken of the latest 
value of fsUrpfDrops. Subtracting from this the snapshot 
of fsUrpfDrops at the start of the current window of time 
gives the number of packets dropped.  
              
The drop rate is 
computed every fsUrpfComputeInterval seconds. As an 
example, let fsUrpfDropRateWindow be 300 seconds,
and fsUrpfComputeInterval 30 seconds. Every 30 seconds,
the drop count five minutes previous is subtracted
from the current drop count, and the result is divided
by 300 to arrive at the drop rate.
              
At device start-up, until the device has been up more than
fsUrpfDropRateWindow, when drop rate is computed,
the value of fsUrpfDrops is divided by the time the
device has been up.
After the device has been up for fsUrpfDropRateWindow,
when drop rate is computed, the number of packet drops counted 
from interval start time to the computation time is divided 
by fsUrpfDropRateWindow.
              
Changes to fsUrpfDropRateWindow are not reflected in this
object until the next computation time.
              
The rate from the  most recent computation is the value 
fetched until the subsequent computation is performed.

MIB

FS-URPF-MIB

OID

.1.3.6.1.4.1.52642.1.1.10.2.46.0.2.1.1.3

Type

column

Access

readonly

Status

current

Units

packets per second

Parent

fsUrpfEntry

Table

fsUrpfTable

Siblings

2