03-12-2023 06:32 PM - edited 03-12-2023 06:48 PM
I have a stack of 9500s with a link down to a 3750 via fiber. Started seeing some issues with video choppiness from equipment connected to the 3750. Looking at the link side on the 9500 I see a fair amount of input/CRC errors and after changing both the SFP and fiber patch to the patch panel it made no difference. I see low power level alarms in the logs on the 9500 side as well but nothing on the 3750 side which is clean.
Is it safe to say something in the path is bad?
TwentyFiveGigE1/0/45 is up, line protocol is up (connected)
Hardware is Twenty Five Gigabit Ethernet, address is e41f.7bb6.58ad (bia e41f.7bb6.58ad)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseSX SFP
input flow-control is on, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:16, output 00:00:00, output hang never
Last clearing of "show interface" counters 06:50:02
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 9000 bits/sec, 10 packets/sec
5 minute output rate 22000 bits/sec, 12 packets/sec
318147 packets input, 42252690 bytes, 0 no buffer
Received 2803 broadcasts (2337 multicasts)
3 runts, 0 giants, 0 throttles
6520 input errors, 204 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 2337 multicast, 0 pause input
0 input packets with dribble condition detected
382094 packets output, 74731489 bytes, 0 underruns
Output 8767 broadcasts (0 multicasts)
0 output errors, 0 collisions, 0 interface resets
0 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
3750 side:
GigabitEthernet1/1/2 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is b0fa.eb1b.0cb2 (bia b0fa.eb1b.0cb2)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseSX SFP
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:03, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 10000 bits/sec, 11 packets/sec
5 minute output rate 11000 bits/sec, 11 packets/sec
379496 packets input, 73812839 bytes, 0 no buffer
Received 61448 broadcasts (52717 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 52717 multicast, 0 pause input
0 input packets with dribble condition detected
322929 packets output, 42019057 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 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
03-12-2023 07:13 PM
@the-lebowski wrote:Last clearing of "show interface" counters 06:50:02
On the 9500, post the complete output to the command "sh controll e Twe 1/0/45".
03-13-2023 06:44 AM - edited 03-13-2023 07:30 AM
Yeah I cleared those counters before I swapped the patch and SFP to see if they would increment after the fact.
r19500#show controllers e twentyFiveGigE 1/0/45
Transmit TwentyFiveGigE1/0/45 Receive
238894429040 Total bytes 100570422562 Total bytes
277548510 Unicast frames 222952279 Unicast frames
192666023726 Unicast bytes 83620926190 Unicast bytes
278345056 Multicast frames 147484794 Multicast frames
38561918928 Multicast bytes 16861086081 Multicast bytes
72164024 Broadcast frames 1224060 Broadcast frames
7666486386 Broadcast bytes 1 Broadcast bytes
0 System FCS error frames 0 IpgViolation frames
0 MacUnderrun frames 0 MacOverrun frames
0 Pause frames 0 Pause frames
0 Cos 0 Pause frames 0 Cos 0 Pause frames
0 Cos 1 Pause frames 0 Cos 1 Pause frames
0 Cos 2 Pause frames 0 Cos 2 Pause frames
0 Cos 3 Pause frames 0 Cos 3 Pause frames
0 Cos 4 Pause frames 0 Cos 4 Pause frames
0 Cos 5 Pause frames 0 Cos 5 Pause frames
0 Cos 6 Pause frames 0 Cos 6 Pause frames
0 Cos 7 Pause frames 0 Cos 7 Pause frames
0 Oam frames 0 OamProcessed frames
0 Oam frames 0 OamDropped frames
13239250 Minimum size frames 1141616 Minimum size frames
390376184 65 to 127 byte frames 277915291 65 to 127 byte frames
42934917 128 to 255 byte frames 15487482 128 to 255 byte frames
45414473 256 to 511 byte frames 23729493 256 to 511 byte frames
18024789 512 to 1023 byte frames 19676603 512 to 1023 byte frames
55870868 1024 to 1518 byte frames 40384728 1024 to 1518 byte frames
62197109 1519 to 2047 byte frames 3197386 1519 to 2047 byte frames
0 2048 to 4095 byte frames 9 2048 to 4095 byte frames
0 4096 to 8191 byte frames 0 4096 to 8191 byte frames
0 8192 to 16383 byte frames 0 8192 to 16383 byte frames
0 16384 to 32767 byte frame 0 16384 to 32767 byte frame
0 > 32768 byte frames 0 > 32768 byte frames
0 Late collision frames 9728516 SymbolErr frames
35729 Excess Defer frames 4264 Collision fragments
0 Good (1 coll) frames 3428 ValidUnderSize frames
0 Good (>1 coll) frames 0 InvalidOverSize frames
0 Deferred frames 0 ValidOverSize frames
0 Gold frames dropped 156984 FcsErr frames
0 Gold frames truncated
0 Gold frames successful
0 1 collision frames
0 2 collision frames
0 3 collision frames
0 4 collision frames
0 5 collision frames
0 6 collision frames
0 7 collision frames
0 8 collision frames
0 9 collision frames
0 10 collision frames
0 11 collision frames
0 12 collision frames
0 13 collision frames
0 14 collision frames
0 15 collision frames
0 Excess collision frames
LAST UPDATE 589 msecs AGO
03-13-2023 07:25 AM
hardcoded the MTU size in both side.
03-13-2023 07:26 AM
Are you saying to hardcode the MTU on both sides?
03-13-2023 05:43 PM
Yes
03-13-2023 05:47 PM
I can't on the 3750 side, at least not on the interface itself. The only thing I can do is set the system and routing MTU but I don't have the option to set the MTU on the physical interface being used for the uplink.
3750hq#conf t
Enter configuration commands, one per line. End with CNTL/Z.
3750hq(config)#int gi1/1/2
3750hq(config-if)#mtu?
% Unrecognized command
interface GigabitEthernet1/1/2
description Uplink to U-9500
switchport trunk allowed vlan xx,xxxx
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
03-13-2023 02:47 PM
@the-lebowski wrote:9728516 SymbolErr frames 4264 Collision fragments 3428 ValidUnderSize frames 156984 FcsErr frames
Describe the physical link. Is this a single patch cable or is there a horizontal cabling plant involved?
03-13-2023 05:12 PM
03-13-2023 09:44 PM
Use a different pair of fibre. The line errors are significant and points to a Layer 1 issue. If using a different pair of fibre plant to the first floor works, then get the original pair investigated for a potential break in the glass.
03-14-2023 07:01 AM
I figured as much. Thanks for your help.
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