Connexion between nexus 3k and catalyst 2960 not coming up

[Rowlands Price]

Hi support

i connected a nexus 3k to catalyst 2960 using SFP with fiber but the interfaces not coming UP.

From the 3k side the interface is blinking and the port is connected.

From the Cat 2960 the interface is not connected and not blinking.

when i'm using the same SFP modules to connect two catalyst, it's working fine but when mooving to nexus 3k not working

ant ideas please?

Thanks

[Kasun Bandara]

@Rowlands Price can you share the exact switch model details and SFP model numbers. also what you see in console when you plugging the SFP to device? check if your fiber cable is working and RX-TX side is correct.

[Rowlands Price]

@Kasun Bandara  here are the switches model N3K-C36180YC-R & WS-C2960S-48LPS-L the SFP model is Cisco GLC-SX-MM and the fiber used is multimode.

when plugging the SFP to device, it's accepted, but when connecting the fiber, from Cat nothing happened 

from nexus, the port status is "suspend"

i'm not now on site, so cannot connect to devices,

[Kasun Bandara]

@Rowlands Price can you check if you have any LACP config in N3K? also in CAT you should see port up/down notification if your cable is working and have proper RX-TX. as @jeanm02 mentioned , check OS also.

[M02@rt37]

Hello @Rowlands Price 

Please share the configuration port of both Nexus and Catalyst.

Thanks.

[Rowlands Price]

Hello M02, the both ports are trunks

NEXUS

interface Ethernet1/2
switchport
switchport mode trunk
no shutdown

Catalyst 2960

interface GigabitEthernet1/0/28
switchport mode trunk

[M02@rt37]

OK @Rowlands Price 

IOS Version of the Nexus ?

Find here the minimum IOS for you Nexus with that SFP GLC-SX-MM

https://tmgmatrix.cisco.com/?npid=38

[Rowlands Price]

Hi M02

here are the version of nexus dans cat

Nexus

NEXUS# sh version
Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Copyright (C) 2002-2019, Cisco and/or its affiliates.
All rights reserved.

Software
BIOS: version 01.14
NXOS: version 9.3(3)
BIOS compile time: 06/15/2019
NXOS image file is: bootflash:///nxos.9.3.3.bin
NXOS compile time: 12/22/2019 2:00:00 [12/22/2019 14:00:37]

Hardware
cisco Nexus3000 N3K-C36180YC-R Chassis
Intel(R) Xeon(R) CPU D-1528 @ 1.90GHz with 32791872 kB of memory.

Cat 2960

Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 52 WS-C2960S-48LPS-L 15.0(2)SE11 C2960S-UNIVERSALK9-M

[Leo Laohoo]

---

@Rowlands Price wrote:
from nexus, the port status is "suspend"

---

In Nexus, BPDU Guard is permanently enabled.  

Turn BPDU Guard and see if the links go up.

[MHM Cisco World]

Point to check

Show interface status in both SW' see the duplex and speed.

Some sfp port of NSK dont support the autonego of duplex/speed.

If that is issue set it manually.

MHM