03-29-2010 05:19 AM - edited 03-06-2019 10:21 AM
Dear Experts,
We are getting protocol drops on our Ehternet Interface of our core router, every time we run the commant show interface gig 0/1 the counters keep on increasing, kindly update what could be reason for the same.
Please find the Details as below
======================================================================================
RTR1#sh int gigabitEthernet 0/2
GigabitEthernet0/2 is up, line protocol is up
MTU 1500 bytes, BW 92160 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 100/255, rxload 11/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, media type is RJ45
output flow-control is XON, input flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:50:55
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 8301
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 4207000 bits/sec, 4065 packets/sec
5 minute output rate 36188000 bits/sec, 8224 packets/sec
12811303 packets input, 1534544971 bytes, 0 no buffer
Received 54 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 5 multicast, 0 pause input
0 input packets with dribble condition detected
26044169 packets output, 3290592132 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
10 unknown protocol drops
414 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
=========================================================================================
03-29-2010 05:25 AM
Hello Ranjit,
if count increments by one at each execution of show command this should be a specific SW bug.
What device is this, and what IOS image is running on it?
otherwise there are possible reasons for this kind of counter:
receiving STP BPDUs or other L2 signalling protocol from connected switch port
or ISIS hello messages when ISIS is not enabled on router interface
for example we use ISIS and access layer switches complain of these unknown protocol drops because they don't use ISIS
given the very low count in comparison to total traffic this is not something to worry about
Hope to help
Giuseppe
03-29-2010 05:27 AM
its a 7206 Box with the below IOS Image
System image file is "disk2:c7200p-advsecurityk9-mz.124-15.T8.BIN"
Cisco 7206VXR (NPE-G2) processor (revision A) with 917504K/65536K bytes of memory.
03-29-2010 05:29 AM
Hello Ranjit,
this is fine info
but have you noticed if the counter increments by one each time you issue sh interface gi0/2?
Hope to help
Giuseppe
03-29-2010 05:33 AM
Hi
It increases every time, pls check the below output
=====================================================================
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
71 unknown protocol drops
475 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
72 unknown protocol drops
476 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
73 unknown protocol drops
477 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
74 unknown protocol drops
478 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
75 unknown protocol drops
479 unknown protocol drops
SRTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
76 unknown protocol drops
480 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
77 unknown protocol drops
481 unknown protocol drops
=======================================================================
03-29-2010 05:39 AM
Hello Ranjit,
as you see you are generating these unknown protocol drops by yourself !!!
to get rid of this you should upgrade to a later IOS image
like
sh ver | inc image
System image file is "disk2:c7200p-advsecurityk9-mz.124-20.T.bin"
sh int gi0/2 | inc unknown
0 unknown protocol drops
router#sh int gi0/2 | inc unknown
0 unknown protocol drops
router#sh int gi0/2 | inc unknown
0 unknown protocol drops
my box looks like free of this small issue
but I would wait to have other reasons to perform an upgrade
Hope to help
Giuseppe
05-02-2012 08:58 AM
Hi - looks like you listed 12.4(24)T1 in the bug and fixed lists.
No worries. I can search the bug info to confirm the fixed ver of 12.4(24)Tx.
03-29-2010 05:42 AM
Hi
It increases every time, pls check the below output
=====================================================================
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
71 unknown protocol drops
475 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
72 unknown protocol drops
476 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
73 unknown protocol drops
477 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
74 unknown protocol drops
478 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
75 unknown protocol drops
479 unknown protocol drops
SRTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
76 unknown protocol drops
480 unknown protocol drops
RTR1#$aces gigabitEthernet 0/2 | i unknown protocol drops
77 unknown protocol drops
481 unknown protocol drops=======================================================================
Hi Ranjit,
It is a bug in your ios Cisco Bug CSCsx18388which was first found in the below version
12.5TPI1
12.4(15)T8
12.4(23.4)T
12.4(23.7)T
12.4(24)T1
and then which are fixed in the following version
12.4(18e)M
12.4(23.15.6)PIC1
12.4(15)T9
15.0(1)M
12.4(24)T1
12.4(24)YG
12.4(24)GC1
12.4(24)MD
15.1(0.2)PI12a
15.1(0.10)T
12.4(24)YE
for more information about your problem just check out the below message related to bug details
"Unknown protocol drops" counter is incremented by one at each sh int | |
Symptom: "Unknown protocol drops" counter is incremented by one at each "show interfaces" command execution Conditions: "unknown protocol drops" counter getting incremented for "down" interface's also Workaround: No work around available |
Remember to rate the helpful post
Ganesh.H
03-29-2010 05:55 AM
Dear All,
No Work around for the same???
Also in the IOS suggested any criticals bugs in the same??
Thanks,
Ranjit
11-29-2010 10:33 PM
I know this is an old conversation but the most likely cause of your issue is cdp. Enable cdp on your interface or disable cdp on your next connected device.
11-30-2010 04:01 AM
Unknown protocol drops reports the packets with unknown or un-configured protocol on a per interface basis. Therefore it can be any protocol that the router doesn’t recognize.
it means if you have disbaled CDP on teh router interface and enabled on other end , when both starts to speak over the CDP packets you router dont get recognised
it was cisco BUG with ID-CSCsx18388
go through the below link - a IOS upgrade will fix your problem
http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCsx18388 (neec CCO login)
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