runts, giants and throttles

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show interface is maybe the most famous command that is entered when we start troubleshooting.
Interpreting the output of this command is like reading the results of the blood analysis, some results are easy to understand, while others are very cryptic but very useful to take us to another level of troubleshooting!

Let’s see runts, giants an throttles:

GigabitEthernet1/0/1 is up, line protocol is up (connected) 
  Hardware is Gigabit Ethernet, address is e05f.b9a5.3801 (bia e05f.b9a5.3801)
  Description: OSPF to DATACENTER CORE
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, 
     reliability 255/255, txload 5/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported 
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:11, output 00:00:05, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 97666
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 2750000 bits/sec, 1693 packets/sec
  5 minute output rate 22540000 bits/sec, 3884 packets/sec
     445938631425 packets input, 234464136350270 bytes, 0 no buffer
     Received 1746434825 broadcasts (1554550409 multicasts)
     54 runts, 33 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 1554550409 multicast, 0 pause input
     0 input packets with dribble condition detected
     520224845742 packets output, 321534935657852 bytes, 0 underruns
     0 output errors, 0 collisions, 1 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

RUNTS are frames smaller than the MTU defined on the interface with correct CRC values (in this case < 1500)

GIANTS are frames larger than the MTU defined on the interface (in this case > 1500)

THROTTLES are frames dropped or suspended due to buffer or processor overload. In this case a complete analisys of the device state is required (Cpu, Ram, Backplane saturation, ecc.)

in Huawei devices throttles values is replaced with DropEvents

GigabitEthernet0/0/14 current state : UP
Line protocol current state : UP
Description: OSPF Network
Route Port,The Maximum Frame Length is 9216
Internet protocol processing : disabled
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 384c-4fbb-3411
Current system time: 2019-09-08 12:52:13+01:00
Port Mode: COMMON FIBER, Transceiver: 1000_BASE_SX_SFP
Speed : 1000,   Loopback: NONE
Duplex: FULL,   Negotiation: ENABLE       
Mdi   : NORMAL, Flow-control: DISABLE
Last 300 seconds input rate 3170368 bits/sec, 1090 packets/sec
Last 300 seconds output rate 15399928 bits/sec, 3396 packets/sec
Input peak rate 999373800 bits/sec, Record time: 2019-06-04 09:31:57
Output peak rate 998988976 bits/sec, Record time: 2019-06-04 09:56:55

Input:  105550025617 packets, 82964626612351 bytes
  Unicast:               105540285417,  Multicast:                     9714972
  Broadcast:                    25228,  Jumbo:                               0
  Discard:                          0,  Pause:                               0
  Frames:                           0

  Total Error:                      0
  CRC:                              0,  Giants:                              0
  Jabbers:                          0,  Fragments:                           0
  Runts:                            0,  DropEvents:                          0
  Alignments:                       0,  Symbols:                             0
  Ignoreds:                         0

Output:  186123595153 packets, 165445346829891 bytes
  Unicast:               186110591856,  Multicast:                    12971986
  Broadcast:                    31311,  Jumbo:                               0
  Discard:                          0,  Pause:                               0

  Total Error:                      0
  Collisions:                       0,  ExcessiveCollisions:                 0
  Late Collisions:                  0,  Deferreds:                           0
  Buffers Purged:                   0     
                                          
    Input bandwidth utilization threshold : 90.00%
    Output bandwidth utilization threshold: 90.00%
    Input bandwidth utilization  : 0.32%  
    Output bandwidth utilization : 1.54%  

Happy Monday!

.glitchlist crew

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