Cabletron Systems SPECTRUM TRMMIM, User Manual

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Ring Map
3-18 Viewing Ring-level Information
buffers. Note that this counter reports the number of
times frames were dropped for lack of buffering, not the
number of frames dropped. Although this is considered a
non-isolating error, you can assume that the adapter
reporting the error is at fault. If the error occurs
frequently, you may want to consider replacing the
reporting station’s NIC card.
Frame Copied Errors The number of frames addressed to the associated station
that had the A (Address Recognized Indicator) bits
already set to 1 when the station received the frame. This
indicates that an electrical line disturbance has corrupted
the token, or that there is a duplicate address on the ring
(either a station with a shared administratively assigned
address, or a transparent bridge that has set the bit).
Token Errors The number of times the associated station, while acting
as the active monitor, has detected an error that required
the transmission of a token (either because a frame was
lost, or a token or frame has recirculated the ring). Note
that this error can only be reported by a station that is, or
was previously, the active monitor for the ring.
Frequency Errors The number of times the associated station detected that
the incoming signal’s frequency differed from the
expected frequency by more than allowed by the IEEE
802.5 standard (.6%). Frequency is measured by an
on-board crystal oscillator on each network interface.
This could indicate an error in the reporting station’s
oscillator, the Active Monitor, or any station between the
two; it happens more often on 16 Mbps rings than on 4
Mbps rings, and can also be a symptom of too many
stations on the ring. When a station detects this
condition, it will begin a monitor contention process to
select a new Active Monitor.
Changing the Station Labels
Initially, each station in the ring map is labelled by MAC address
; addresses are displayed in Canonical format (reverse
bit order).
You can change the map’s station labels to reflect one of the following:
Board/Port/Drop – This label displays each station’s board and port index, as well
as its administratively assigned drop number (if one has been assigned).