12-05-2018 01:50 AM - edited 03-08-2019 04:44 PM
I have 4 stacks switch WS-C2960X connected to N5K-C5672 through VPC.
and from 2960X side use LACP portchannel.
CRC keeps increasing, only on connection to Nexus02, no CRC connection to Nexus01.
I've tried changing SFPs, changing Ports, changing Cables.
here my show commands..
SW01#sh cdp ne | b Device
Device ID Local Intrfce Holdtme Capability Platform Port ID
Nexus02 Gig 2/0/50 125 R S I C N5K-C5672 Eth 1/29
Nexus01 Gig 1/0/50 159 R S I C N5K-C5672 Eth 1/29
Total cdp entries displayed : 2
SW01#sh int gi 1/0/50 | inc error
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 output errors, 0 collisions, 0 interface resets
SW01#sh int gi 2/0/50 | inc error
66930 input errors, 66450 CRC, 0 frame, 0 overrun, 0 ignored
0 output errors, 0 collisions, 0 interface resets
SW01#
===================
SW02#sh cdp ne | b Device
Device ID Local Intrfce Holdtme Capability Platform Port ID
Nexus02 Gig 1/0/49 122 R S I C N5K-C5672 Eth 1/30
Nexus01 Gig 2/0/49 134 R S I C N5K-C5672 Eth 1/30
SW02#sh int gi 1/0/49 | inc error
43369 input errors, 42988 CRC, 0 frame, 0 overrun, 0 ignored
0 output errors, 0 collisions, 0 interface resets
SW02#sh int gi 2/0/49 | inc error
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 output errors, 0 collisions, 0 interface resets
SW02#
===================
SW03#sh cdp ne | b Device
Device ID Local Intrfce Holdtme Capability Platform Port ID
Nexus02 Gig 1/0/52 177 R S I C N5K-C5672 Eth 1/31
Nexus01 Gig 2/0/52 145 R S I C N5K-C5672 Eth 1/31
Total cdp entries displayed : 2
SW03#sh int gi 1/0/52 | inc error
2758140 input errors, 38073 CRC, 0 frame, 0 overrun, 0 ignored
0 output errors, 0 collisions, 0 interface resets
SW03#sh int gi 2/0/52 | inc error
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 output errors, 0 collisions, 2 interface resets
SW03#
connection looks good, but not sure whats gonna happen in future.
12-05-2018 02:15 AM
Are duplex configured in the same way on both devices?
Duplex mismatch can cause CRC.
Regards.
12-05-2018 02:22 AM
Check also this link:
https://community.cisco.com/t5/switching/nexus-5ks-to-2960-x-stack-crc-errors/td-p/2775071
CRC could be explained by the switching modality. The cut through mode forwards bad frames transparently from other ports.
So check CRC errors on all ports of the switch.
Regards.
12-05-2018 05:54 PM
12-05-2018 05:51 PM
12-05-2018 03:14 AM
12-05-2018 06:00 PM
here i post both ports connected to N5k01 & N5k02
i found there's different in FCS errors.
12-05-2018 09:44 PM - edited 12-05-2018 09:46 PM
Let me repeat myself: DON'T PUT ANY FILTERS ON.
If it's a "secret" then change the IP address or raise a TAC Case.
12-05-2018 10:11 PM
got it..
on 2960X stack..
12-05-2018 10:17 PM
12-06-2018 01:10 AM
Many thanks for the explanation Leo.. :)
i've tried to change port.
SW01 both port-channel member connect to N5K01, after 30mins await no more CRC from SW01.
i believe should be no problem with the SFP and cabling.
but this.. SW02 both port-channel member connect to N5K02, both ports get CRC.
and i checked all switch port connect to N5K02 got CRC.
both nexus running same System version: 7.1(0)N1(1b)
12-06-2018 02:05 AM - edited 12-06-2018 02:07 AM
Here's one way of testing: Swap the fibre between Gi 1/0/50 and Gi 2/0/50.
If the CRC errors go to Gi 1/0/50 then we are sure it's an issue. Since this is fibre, get someone to do an OTDR test of the entire link.
By the way, is the fibre link between the two OM3/OM4?
And how is this path linked together? Is it:
2960 stack < --- > patch cord < -- > FOBOT < -- > fibre optic cable < -- > FOBOT < -- > patch cord < -- > Nexus?
(I want to know how many patch cord/cords and/or how many jumpers, etc.)
12-06-2018 03:11 AM
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