WS-C4510R-E / Troubleshooting

[Jhonadms]

We are having some issues with multiple drops on several interface on you 4510, please advice.

FastEthernet1/1 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2679693

FastEthernet1/2 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2668494

FastEthernet1/3 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2675094

FastEthernet1/4 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2672673

FastEthernet1/5 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 5039021

FastEthernet1/6 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2671220

FastEthernet1/7 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2677973

FastEthernet1/8 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2671614

FastEthernet1/9 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2667831

FastEthernet1/10 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2669575

FastEthernet1/11 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2675859

FastEthernet1/12 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 3772555

FastEthernet1/13 is up, line protocol is up (connected)

  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2669431

[Georg Pauwen]

Hello,

what does the configuration look like, do you have any QoS configured ? Which IOS version are you running (post the output of 'sh ver') ?

[Mark Malone]

To adds to Georges post , are there gig device connected to these fast ethernet ports you maybe easily oversubscribing the ports ?

You will nearly always see drops but the drop rate should stay below 1 % if not you have an issue as per Cisco standard , have you calculated the drop rate compared to the data rate going through the ports to see what percentage it is ?

[MUHAMMAD TAYYAB MUNIR · Accepted solution]

Hi,

Please answer the following question in order to understand;

1) Device Role?

2) it is downlink or uplinks?

3) Access interface or Trunk?

4) Connected end host devices?

5) Any special QoS configuration applied?

6) When do you start facing this issue and its new devices or old?

7) Did you check is there any broadcast storm in your network usually when broadcast devices are connected you will face a similar issue?

 BR,

Tayyab - www.tayyabmunir.com 

[Jhonadms]

Hi @MUHAMMAD TAYYAB MUNIR

• Device working as a Aggregator.
• down stream
• cisco switches 2960/3560
• no qos
• Last night started and it is old deployment.
• I just noticed huge Broadcast is there hold a moment let me trace the mac addresses

Thanks

Jhon

[MUHAMMAD TAYYAB MUNIR · Accepted solution]

Hi Jhon,

I got you, The AG switch is receiving the high number of broadcast traffic coming from broadcast devices and a result the interface drop the packets after the TX buffer getting full.

Solution: Please trace the devices and drop the mac on the access device to stop the packets being sent.

Please don't forget to rate!

[Leo Laohoo]

IF this switch is acting as a Distro, what kind of line card? Not all like cards, particularly line cards designed for access switching have deep buffers.
What happens if you move the links to the supervisor card?

[Georg Pauwen]

What device was causing the broadcasts ? And how did you finally resolve this ?

[Jhonadms]

HI,

We found TP-Link devices are connected with the 2960 switch and its generating huge Broadcast in the network, I drop the mac address of the TP-Link device and clear the counter so far everything is OK.

BR

Jhon

[Mark Malone]

set storm control on the Cisco ports especially going back to the TP switches make sure it doesn't happen again

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SX/configuration/guide/book/storm.html