Output errors and interface resets.

Question

hi Netpros,
Any idea as to what could be causing output errors and interfece resets on the radio interfaces .. The output interpreter from Cisco does not show any information about the radio interfaces
please see this output after clearing the counters
Dot11Radio0 is up, line protocol is up
Hardware is 802.11G Radio, address is 0015.c7a8.3d90 (bia 0015.c7a8.3d90)
MTU 1500 bytes, BW 54000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 1., loopback not set
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:07, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/962/0 (size/max/drops/flushes); Total output drops: 181678
Queueing strategy: fifo
Output queue: 0/30 (size/max)
5 minute input rate 4000 bits/sec, 6 packets/sec
5 minute output rate 1000 bits/sec, 1 packets/sec
39213813 packets input, 3905641263 bytes, 0 no buffer
Received 53803 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
21236022 packets output, 3766719027 bytes, 0 underruns
11617 output errors, 0 collisions, 25 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Any input is much appreciated.

Answer 1

Let's take a look at what you're worried about: 11,617 output errors divided by 21,236,022 packets output = 0.05% loss. Not really much to worry about there.
As for the 25 interface resets, that's one reset for every 849,441 output packets. Again, nothing really to worry about, but one does wonder why those numbers are not zero.
So how about taking a closer look at the following line you reported:
Input queue: 0/75/962/0 (size/max/drops/flushes); Total output drops: 181678
Notice in particular the "Input queue drops = 962" and more importantly, the "Total output drops = 181,678". You can find detailed troubleshooting information about these problems at: http://www.cisco.com/warp/public/63/queue_drops.html to help you figure out what the actual problem is and whether or not it can be rectified by fine tuning your parameters.
FYI: Here is a standard definition of Output related errors: (taken from http://www-commeng.cso.uiuc.edu/uiucnet/reports/glossary.html )
Output Errors
- Output errors are the sum of all the output errors that occur on an interface.
Out Success With Retry Errors
- Out Success With Retry errors are output errors which indicate that a frame successfully transmitted after one or more collisions. Out Success With Retry Errors are the number of frames that experienced a a collision and retransmit before success. The total collisions divided by the number of Out Success With Retry errors will provide the average number of collisions per packet transmitted with collisions.
Out of Window Collisions Errors
- Out of Window Collisions are a type of output error. Out of window collision errors occur when a frame in the process of being transmitted collides with another frame. This error usually occurs either when some interface on the network fails to defer or the network has too many stations. (See Late Collisions.)
Output Discard Errors
- Output Discards are output errors that occur when the router has to throw a packet out instead of queuing it for transmission on the Ethernet. Output discard errors usually indicate that the network has more traffic than it can handle. They may also indicate a software discard such as no route to destination.
Output FIFO Overrun Errors
- FIFO Overruns are a type of output error. Output FIFO Overruns occur when the output queue in the adapter underflowed while putting a frame on the wire. This problem occurs when the interface is not receiving bits of the frame fast enough.
Walt