[c-nsp] Ignore counters on 2950 switch

[krunal shah]

hi I am troubleshooting increasing ignore counts on 2950 to 2950 switch to
switch interface. This counter is increasing at same rate as "no-buffer"
under show interface. When I did "show interface fast 0/2 counter errors"
The counter rcv-error also increasing at same rate.

There are 4 2950 switches connected in ring topology and all switch to
switch ports has ignore errors with no-buffer and rcv-error.
2950#sho run int f0/2
Building configuration...

Current configuration : 57 bytes
!
interface FastEthernet0/2
 speed 100
 duplex full
end
2950#sho int f0/2 counters error

Port        Align-Err    FCS-Err   Xmit-Err    Rcv-Err UnderSize
Fa0/2               0          0          0       1759         0

Port      Single-Col Multi-Col  Late-Col Excess-Col Carri-Sen     Runts
Giants
Fa0/2              0         0         0          0         0
0         0
2950#sho int f0/2
FastEthernet0/2 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0009.7c58.9482 (bia 0009.7c58.9482)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:03, output 00:00:01, output hang never
  Last clearing of "show interface" counters 2d01h
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 34000 bits/sec, 4 packets/sec
  5 minute output rate 39000 bits/sec, 5 packets/sec
     3721996 packets input, 2706010843 bytes,* 1759 no buffer*
     Received 26164 broadcasts (18616 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, *1759 ignored*
     0 watchdog, 18616 multicast, 0 pause input
     0 input packets with dribble condition detected
     2977227 packets output, 1049227263 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out
2950#sho int tru

Port        Mode         Encapsulation  Status        Native vlan
Fa0/1       desirable    802.1q         trunking      1

Port      Vlans allowed on trunk
Fa0/1       1-4094

Port        Vlans allowed and active in management domain
Fa0/1       1

Port        Vlans in spanning tree forwarding state and not pruned
Fa0/1       1


 From my research I have been able to find out following.

Ignored:-
Shows the number of received packets ignored by the interface because the
interface hardware ran low on internal buffers. These buffers are different
from the system buffers mentioned previously in the buffer description.
Broadcast storms and bursts of noise can cause the ignored count to be
increased.
--------------------------------------------
No buffers:-
Gives the number of received packets discarded because there was no buffer
space in the main system. Compare this with the ignored count. Broadcast
storms on Ethernet networks are often responsible for no input buffer
events.

--------------------------------------------
Rcv-err in show interface fast 0/1 counter error
Receive error are seen on port Fa0/1.This indicates that the receive
buffers are full and could lead to packet loss. This counter also
increments when there is excessive traffic through the switch.

All above 3 counters are increasing with exactly same rate.
When I looked at the interface traffic its very low and in some kbps. There
are no VLANs on any of the switch and all users connected to the switch are
in same broadcast domain.

Can anyone help in finding out reason for this counters and how to reduce
it??

Krunal