interface ignores on a vlan

[Stuart Gall]

In the docs it says that ignores occur when the interface hardware runs low on buffers.

What does it mean when I see ignores (lots of them) on a Vlan but I do not see them on the trunk interface.
This is the management VLAN on a switch.

Is it possible that these are packets on the vlan with a different ip to the management interface ?

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[Arumugam Muthaiah]

Hi Stuart,

ignored means that the number of received packets ignored by the interface because the interface hardware ran low on internal buffers.

Common Causes: Broadcast storms and bursts of noise can cause the ignored count to be increased

Please verify the no buffer counter at the same time, whether does it incrementing same rate as ignored count

no buffer indicates that the number of received packets discarded because there is no buffer space.

Common Causes: Compare with ignored count. Broadcast storms can often be responsible for these events.

Refer:

http://www.cisco.com/en/US/partner/products/hw/switches/ps708/products_tech_note09186a008015bfd6.shtml

Regards,

Aru

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[Stuart Gall]

This is on the management network of the switch, really low traffic. I don't understand why I would get ignores.
If there is noise I should get ignores on the trunk and not the vlan, I would have thought.
I will try a debug ip packet on Monday, and see if I can figure this out.


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[Stuart Gall]

Unfortunately my access does not allow me to open that link.

I tried adding permanent buffers but it did not help. I am getting an ignore every few seconds.
This makes no sense

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output never, output hang never
Last clearing of "show interface" counters 04:51:04
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 8000 bits/sec, 7 packets/sec
5 minute output rate 3000 bits/sec, 5 packets/sec
123788 packets input, 19314228 bytes, 0 no buffer
Received 45684 broadcasts (0 IP multicast)
0 runts, 0 giants, 57 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 22842 ignored
95451 packets output, 7876499 bytes, 0 underruns
0 output errors, 0 interface resets
0 output buffer failures, 0 output buffers swapped out


show buffers
Buffer elements:
499 in free list (500 max allowed)
286643977 hits, 0 misses, 0 created

Public buffer pools:
Small buffers, 104 bytes (total 50, permanent 50, peak 103 @ 7w0d):
50 in free list (20 min, 60 max allowed)
135560265 hits, 41 misses, 86 trims, 86 created
0 failures (0 no memory)
Middle buffers, 600 bytes (total 25, permanent 15, peak 43 @ 7w0d):
24 in free list (10 min, 30 max allowed)
18203352 hits, 16640 misses, 13518 trims, 13528 created
149 failures (0 no memory)
Big buffers, 1524 bytes (total 25, permanent 25):
25 in free list (5 min, 20 max allowed)
2807091 hits, 4975 misses, 6588 trims, 6588 created
129 failures (0 no memory)
VeryBig buffers, 4520 bytes (total 9, permanent 0, peak 9 @ 7w0d):
9 in free list (0 min, 10 max allowed)
3598288 hits, 15 misses, 0 trims, 9 created
12 failures (0 no memory)
Large buffers, 5024 bytes (total 1, permanent 0, peak 2 @ 7w0d):
1 in free list (0 min, 5 max allowed)
2 hits, 10 misses, 1332 trims, 1333 created
10 failures (0 no memory)
Huge buffers, 18024 bytes (total 1, permanent 0, peak 2 @ 7w0d):
1 in free list (0 min, 2 max allowed)
2 hits, 8 misses, 1332 trims, 1333 created
8 failures (0 no memory)

Interface buffer pools:
Calhoun Packet Receive Pool buffers, 1560 bytes (total 256, permanent 256):
223 in free list (0 min, 256 max allowed)
73873095 hits, 0 misses

show buffers input-interface vlan 202

Header DataArea Pool Rcnt Size Link Enc Flags Input Output



Header DataArea Pool Rcnt Size Original Flags caller_pc


Header DataArea Pool Rcnt Size Link Enc Flags Input Output


show buffers failures
Caller Pool Size When
0x802D1C34 Big 646 4w0d
0x802D1C34 Big 790 3w6d
0x802D1C34 Big 790 3w6d
0x802D1C34 Big 683 2w6d
0x802D1C34 Big 683 2w6d
0x802D1C34 Big 790 2w5d
0x802D1C34 Middle 300 1w0d
0x802D1C34 Middle 154 6d03h
0x802D1C34 Middle 138 6d03h
0x802D1C34 Middle 138 6d03h



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