ASR1002-X shows TailDrops at Tengiga 0/1/0

[xge]

Hi Team,

How could I identify where the tail drops happened ?

System image file is "bootflash:asr1002x-universalk9.03.13.02.S.154-3.S2-ext.SPA.bin"

show plat hard qfp active statistics drop
-------------------------------------------------------------------------
Global Drop Stats                         Packets                  Octets 
-------------------------------------------------------------------------
BadIpChecksum                              463378               327821064 
Disabled                                      111                   72306 
Discard                                 269983399             22915440329 
EssBadSessUidb                               4009                  779390 
EssNoEncapInfo                                  7                     316 
EssUnsupPktType                               924                   89934 
GtpBadOptions                                  12                     504 
Icmp                                         2498                  178153 
IpFormatErr                                    15                    5419 
IpFragErr                                11532050             17758955000 
IpTtlExceeded                             2857517               480499032 
Ipv4Acl                                  18863404              3048092240 
Ipv4Martian                                   817                  101948 
Ipv4NoAdj                                     106                  114541 
Ipv4NoRoute                                   452                   34742 
Ipv4Null0                              4953375967            404999143544 
Ipv4Unclassified                          3951310               296140332 
L2tpNoSession                                2456                 2322883 
L2tpPktBadLen                                   1                      54 
MplsNoAdj                                      66                   15745 
QosPolicing                              14796084             12704846653 
ReassTimeout                                   19                   34268 
TailDrop                                131036575            115514564776    <<<<<<<<<<<<<
UnconfiguredIpv4Fia                      14096334              5025060263 
UnconfiguredIpv6Fia                       7232724              1657378241 
Unresolved                                     43                   12040

show int ten0/1/0 | i drop
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 131036906   <<<<<<<<<<
  5 minute input rate 48323000 bits/sec, 28605 packets/sec
  5 minute output rate 482449000 bits/sec, 44342 packets/sec    0 unknown protocol drops

[Philip D'Ath]

Check out this guide.

http://www.cisco.com/c/en/us/support/docs/routers/asr-1000-series-aggregation-services-routers/110531-asr-packet-drop.html

Search for the word tail.

[xge]

The CCO link has been read several times before the issue was raised in the Forum.  No clue was found in the link.  

[Vinit Jain]

Hello,

Is there a QoS policy on the interface. Could you please share the running config of the interface. There are two conditions in which similar behavior is noticed (leaving QoS aside)

1. when there is extra traffic (sometimes u can even notice overrun counters on the interface but on ASR1k, you will see tail drops coz the forwarding decision is done on the ESP card.)

2. When there is back pressure noticed on the ESP card. have come across couple of those instances.

If you are having QoS, then you might want to look at the configured policy.

Regards

Vinit

[xge]

Hi Vinit, no QoS config.  Please find the command output from the CCO link and brief config.  Harry