"Warning-Packet Discard(s)" Message

[wavess]

Hi All

Got a weird one for you.  thought someone on here might have an idea of what is going on or can point me in a direction.   haven't seen this before.  

interface is active, connection is up.  nothing is listed in the log for the switch on gig1/0/43, which is the port in question.

I have a cisco 9200 access switch.  it is connected to a net clock appliance.  

the port is on a management vlan.  the ip of the net clock is within that vlan.  

i can ping the net clock from the switch.  

our network monitoring software is reporting this:

packet discard(s)

level: warning

trigger condition: greater than 10,000 packet discards on a device over 5 minutes.

[wavess]

we are also seeing this message one other times but on a different switch.  Getting a "warning alert paused for entity" and a "warning packet discards" messages.  both in our network monitoring software.  again, interface is up, connected, and nothing in the log for that port.  this info might not be relevant to the above issue, but thought it might be related.

[Reza Sharifi]

Hi,

Do you see any errors, when you do a "sh interface gig1/0/43"?

If you do a continuous ping to the clock, do you see any packet loss?

If the interface is clean and there is no packet loss when you ping the clock, then it may be an issue with the monitoring software reporting.

HTH

[wavess]

Hey Reza.  I see this.  no output errors.  many unknown protocol drops.  it seems that is the issue - the unknown protocol drops.  

did a continuous ping from switch to netclock with this command, and no issues.

ping 10.2.4.40 repeat 100000
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (100000/100000), round-trip min/avg/max = 1/1/296 ms

Output queue: 0/40 (size/max)
5 minute input rate 68000 bits/sec, 11 packets/sec
5 minute output rate 254000 bits/sec, 36 packets/sec
135495201 packets input, 66298115462 bytes, 0 no buffer
Received 1640093 broadcasts (1363791 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 1363791 multicast, 0 pause input
0 input packets with dribble condition detected
460767627 packets output, 225898260559 bytes, 0 underruns
Output 170327302 broadcasts (0 multicasts)
0 output errors, 0 collisions, 2 interface resets
765430 unknown protocol drops
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

[Reza Sharifi · Accepted solution]

Hi,

So, based on the interface output you posted, the interface is clean. "Unknown protocol drops" means the device (clock) is communicating via a protocol that the switch does not understand. So, I would look into understanding what protocols the clock supports, and maybe use Wireshark to capture the frames the clock is sending to the switch, and go from there.

HTH

[wavess]

thanks everyone for your input.  i will look into this using wireshark.  sounds like a protocol issue.  appreciate you guys.  thanks again.

[Reza Sharifi]

Good Luck! 

Let us know what you find out.