System information

Troubleshooting Token Ring
Book Title
6-88
CRC The cyclic redundancy checksum generated by the originating LAN station or
far-end device does not match the checksum calculated from the data received. On
a LAN, this usually indicates noise or transmission problems on the LAN
interface or the LAN bus itself. A high number of CRCs is usually the result of a
station transmitting bad data.
frame Number of packets received incorrectly having a CRC error and a noninteger
number of octets.
overrun Number of times the serial receiver hardware was unable to hand receive data to a
hardware buffer because the input rate exceeded the receiver’s ability to handle the
data.
ignored Number of received packets ignored by the interface because the interface
hardware ran low on internal buffers. These buffers are different than the system
buffers mentioned previously in the buffer description. Broadcast storms and
bursts of noise can cause the ignored count to be increased.
packets output Total number of messages transmitted by the system.
bytes output Total number of bytes, including data and MAC encapsulation, transmitted by the
system.
underruns Number of times that the far-end transmitter has been running faster than the
near-end router’s receiver can handle. This may never be reported on some
interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the
interface being examined. Note that this may not balance with the sum of the
enumerated output errors, as some datagrams may have more than one error and
others may have errors that do not fall into any of the specifically tabulated
categories.
collisions Because a Token Ring cannot have collisions, this statistic is nonzero only if an
unusual event occurred when frames were being queued or taken out of the queue
by the system software.
interface resets The number of times an interface has been reset. The interface may be reset by the
administrator or automatically when an internal error occurs.
restarts Should always be zero for Token Ring interfaces.
transitions Number of times the ring made a transition from up to down, or vice versa. A large
number of transitions indicates a problem with the ring or the interface.
Field Description