etherStatsCollisions

The best estimate of the total number of collisions
on this Ethernet segment.
              
The value returned will depend on the location of the
RMON probe. Section 8.2.1.3 (10BASE-5) and section
10.3.1.3 (10BASE-2) of IEEE standard 802.3 states that a
station must detect a collision, in the receive mode, if
three or more stations are transmitting simultaneously.  A
repeater port must detect a collision when two or more
              
stations are transmitting simultaneously.  Thus a probe
placed on a repeater port could record more collisions
than a probe connected to a station on the same segment
would.
              
Probe location plays a much smaller role when considering
10BASE-T.  14.2.1.4 (10BASE-T) of IEEE standard 802.3
defines a collision as the simultaneous presence of signals
on the DO and RD circuits (transmitting and receiving
at the same time).  A 10BASE-T station can only detect
collisions when it is transmitting.  Thus probes placed on
a station and a repeater, should report the same number of
collisions.
              
Note also that an RMON probe inside a repeater should
ideally report collisions between the repeater and one or
more other hosts (transmit collisions as defined by IEEE
802.3k) plus receiver collisions observed on any coax
segments to which the repeater is connected.

MIB

RMON-MIB

OID

.1.3.6.1.2.1.16.1.1.1.13

Type

column

Access

readonly

Status

current

Units

Collisions

Parent

etherStatsEntry

Table

etherStatsTable

Siblings

20