cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
247
Views
0
Helpful
6
Replies
Highlighted
Beginner
Beginner

"no buffer" & "ignored" counter increased on Cisco 2950G GigabitEthernet 0/1

Hi everyone, hope have a good weekend.

 

My switch is connecting to the ISP on Gi0/1. And it's connecting downstream via FastEthernet interface only. Recently I saw there is a lot of "no buffer" and "ignored" error counter. But there is no failure by checking "show buffer"

 

Should I adjust the system buffer? Likes this: https://www.cisco.com/c/en/us/support/docs/routers/10000-series-routers/15091-buffertuning.html

 

Or apply the QoS to control the queue?

 

<LOG>

GigabitEthernet0/1 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 000d.2993.5e19 (bia 000d.2993.5e19)
Description: ISP
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is LX
input flow-control is off, output flow-control is on
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:01, output hang never
Last clearing of "show interface" counters 5d22h
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
30 second input rate 551000 bits/sec, 455 packets/sec
30 second output rate 314000 bits/sec, 104 packets/sec
278502914 packets input, 1387604620 bytes, 1636827 no buffer
Received 2746421 broadcasts (288501 multicast)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 1636827 ignored
0 watchdog, 288501 multicast, 0 pause input
0 input packets with dribble condition detected
70935802 packets output, 2339506744 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

 

#show buffer
Buffer elements:
498 in free list (500 max allowed)
2434735956 hits, 0 misses, 0 created

Public buffer pools:
Small buffers, 104 bytes (total 28, permanent 25, peak 109 @ 7w0d):
27 in free list (20 min, 60 max allowed)
1521669621 hits, 3926 misses, 11251 trims, 11254 created
0 failures (0 no memory)


Middle buffers, 600 bytes (total 27, permanent 15, peak 186 @ 00:29:53, extra 15):
27 in free list (10 min, 30 max allowed)
6101747 hits, 14811 misses, 44428 trims, 44440 created
0 failures (0 no memory)


Big buffers, 1524 bytes (total 6, permanent 5, peak 7 @ 7w0d):
6 in free list (5 min, 10 max allowed)
11343426 hits, 1 misses, 21247 trims, 21248 created
0 failures (0 no memory)


VeryBig buffers, 4520 bytes (total 10, permanent 0, peak 12 @ 7w0d):
10 in free list (0 min, 10 max allowed)
40591211 hits, 7 misses, 4 trims, 14 created
0 failures (0 no memory)


Large buffers, 5024 bytes (total 0, permanent 0):
0 in free list (0 min, 5 max allowed)
0 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)


Huge buffers, 18024 bytes (total 0, permanent 0):
0 in free list (0 min, 2 max allowed)
0 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)

 

Interface buffer pools:
Calhoun Packet Receive Pool buffers, 1560 bytes (total 256, permanent 256):
219 in free list (0 min, 256 max allowed)
432803148 hits, 0 misses

6 REPLIES 6
Highlighted
Hall of Fame Community Legend

Re: "no buffer" & "ignored" counter increased on Cisco 2950G GigabitEthernet 0/1

Post the complete output to the command "sh controller ether Gi 0/1".
Highlighted
Beginner
Beginner

Re: "no buffer" & "ignored" counter increased on Cisco 2950G GigabitEthernet 0/1

Thanks for your reply. Here is the output of command "show controllers eth Gi0/1

 

#sh controllers ethernet-controller Gi0/1

Transmit Receive
1183354638 Bytes 4136747379 Bytes
207039193 Frames 215941087 Frames
137638914 Multicast frames 0 FCS errors
2991851 Broadcast frames 27688793 Multicast frames
0 Pause frames 120426629 Broadcast frames
0 Single defer frames 0 Control frames
0 Multiple defer frames 0 Pause frames
0 1 collision frames 0 Unknown opcode frames
0 2-15 collisions 0 Alignment errors
0 Late collisions 0 Length out of range
0 Excessive collisions 0 Symbol error frames
0 Total collisions 0 False carrier errors
0 Control frames 0 Valid frames, too small
0 VLAN discard frames 0 Valid frames, too large
0 Too old frames 0 Invalid frames, too small
3903140353 Tagged frames 0 Invalid frames, too large
0 Aborted Tx frames 23448723 Discarded frames

Transmit and Receive
2940044303 Minimum size frames
13787608 65 to 127 byte frames
3475285939 128 to 255 byte frames
1023799788 256 to 511 byte frames
1333848619 512 to 1023 byte frames
1830333579 1024 to 1518 byte frames
1870972915 1519 to 1522 byte frames

Highlighted
VIP Mentor

Re: "no buffer" & "ignored" counter increased on Cisco 2950G GigabitEthernet 0/1

Hello,

 

based on your output, I would try and gradually increase the system buffers; observe if the drops decrease. You can start with doubling the values:

 

buffers small max-free 120
buffers small min-free 40
buffers permanent 50
!
buffers middle max-free 60
buffers middle min-free 20
buffers middle permanent 30
!
buffers big max-free 20
buffers big min-free 10
buffers big permanent 10
!
buffers verybig max-free 20
buffers verybig min-free 10
buffers verybig permanent 10

Highlighted
Beginner
Beginner

Re: "no buffer" & "ignored" counter increased on Cisco 2950G GigabitEthernet 0/1

Thanks. I'm thinking to add the small and middle buffers.

Btw, do you know the maxi. buffer on C2950G-24?

Highlighted
Beginner
Beginner

Re: "no buffer" & "ignored" counter increased on Cisco 2950G GigabitEthernet 0/1

Tried to increase the buffer, but still got the same error....

Highlighted
Hall of Fame Community Legend

Re: "no buffer" & "ignored" counter increased on Cisco 2950G GigabitEthernet 0/1

23448723 Discarded frames

This is where the counters are coming from. 

Read THIS and search for the phrase "discarded frames".  

This gist of it is frames get discarded when it sits in the switch's buffer for too long (like food going bad).  

 

CreatePlease to create content
Content for Community-Ad