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4500X-16 output drops: question

msrohman
Beginner
Beginner

Hi all,

 

We have a port on our Cisco 4500X switch (VSS) that is experiencing a lot of output drops.  The port experiencing the output drops is the traffic leaving our data center to our headquarters via a 1Gbps Metro-E circuit. We're not experiencing high bandwidth utilization on the Metro 1Gbps circuit.  Although we haven't clear the counters in a while, the output drops are continuing at a decent clip.

Any idea why there are so many output drops considering the bandwidth utilization doesn't reach 100%? 

!

Cisco IOS Software, IOS-XE Software, Catalyst 4500 L3 Switch Software (cat4500e-UNIVERSALK9-M)

!

Te2/1/3   to_Metro_1Gbps_circuit   routed       full a-1000 1000BaseT

!
!

IL1NP0001WAN#sh int ten2/1/3
TenGigabitEthernet2/1/3 is up, line protocol is up (connected)
  Hardware is Ten Gigabit Ethernet Port, address is 0007.e3ff.fc17 (bia 0007.e3ff.fc17)
  Description: to_Metro_1Gbps_circuit
  Internet address is <IP address>
  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 9/255, rxload 2/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseT
  input flow-control is on, output flow-control is on
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 2276092
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 8638000 bits/sec, 3735 packets/sec
  5 minute output rate 35950000 bits/sec, 5540 packets/sec
  L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  IPv6 L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  IPv6 L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
     62274823016 packets input, 22639883087683 bytes, 0 no buffer
     Received 9302394 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 input packets with dribble condition detected
     110760882640 packets output, 109819304243187 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out
 

 

Thanks in advance.

 

Mike

3 REPLIES 3

Leo Laohoo
VIP Community Legend VIP Community Legend
VIP Community Legend

Do you have QoS enabled?

Hello Leo,

 

No, it does not have QoS enabled on that particular switchport. But there is MQC QoS applied to a few other interfaces on the switch. It should just be using the FIFO queue, right?


!

interface TenGigabitEthernet2/1/3
 description to_Metro_1Gbps
 no switchport
 ip address <ip address>  255.255.255.248
 

!

 

Thanks.

 

Mike

Leo Laohoo
VIP Community Legend VIP Community Legend
VIP Community Legend

Either have traffic shaping or do QoS on the link.

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