Cisco 3850 stack non existing ports are shown

[mario.jost]

Hi guys

We have 3x 3850 Switches in a stack. We do have only the first two switches equipped with a network module. But we can still see the Ports Gi3/1/1 Te3/1/1 Fo3/1/1 and so on...

switch#show inventory
NAME: "c38xx Stack", DESCR: "c38xx Stack"
PID: WS-C3850-12X48U   , VID: V02  , SN: FCW2042XXX

NAME: "Switch 1", DESCR: "WS-C3850-12X48U-S"
PID: WS-C3850-12X48U-S , VID: V02  , SN: FOC2042XXX

NAME: "StackPort1/1", DESCR: "StackPort1/1"
PID: STACK-T1-50CM     , VID: V01  , SN: MOC2039XXX

NAME: "StackPort1/2", DESCR: "StackPort1/2"
PID: STACK-T1-50CM     , VID: V01  , SN: MOC2039XXX

NAME: "Switch 1 - Power Supply B", DESCR: "Switch 1 - Power Supply B"
PID: PWR-C1-1100WAC    , VID: V01  , SN: DTN2034XXX

NAME: "Switch 1 FRU Uplink Module 1", DESCR: "2x1G 2x10G Uplink Module"
PID: C3850-NM-2-10G    , VID: V01  , SN: FOC2042XXX

NAME: "Switch 2", DESCR: "WS-C3850-12X48U-S"
PID: WS-C3850-12X48U-S , VID: V02  , SN: FCW2042XXX

NAME: "StackPort2/1", DESCR: "StackPort2/1"
PID: STACK-T1-50CM     , VID: V01  , SN: MOC2039XXX

NAME: "StackPort2/2", DESCR: "StackPort2/2"
PID: STACK-T1-50CM     , VID: V01  , SN: MOC2039XXX

NAME: "Switch 2 - Power Supply A", DESCR: "Switch 2 - Power Supply A"
PID: PWR-C1-1100WAC    , VID: V01  , SN: DTN2034XXX

NAME: "Switch 2 FRU Uplink Module 1", DESCR: "2x1G 2x10G Uplink Module"
PID: C3850-NM-2-10G    , VID: V01  , SN: FOC2042XXX

NAME: "Switch 3", DESCR: "WS-C3850-12X48U-S"
PID: WS-C3850-12X48U-S , VID: V02  , SN: FCW2042XXX

NAME: "StackPort3/1", DESCR: "StackPort3/1"
PID: STACK-T1-50CM     , VID: V01  , SN: MOC2039XXX

NAME: "StackPort3/2", DESCR: "StackPort3/2"
PID: STACK-T1-50CM     , VID: V01  , SN: MOC2039XXX

NAME: "Switch 3 - Power Supply A", DESCR: "Switch 3 - Power Supply A"
PID: PWR-C1-1100WAC    , VID: V01  , SN: DTN2034XXX

switch#show interfaces description | include /1/
Gi1/1/1                        down           down
Gi1/1/2                        down           down
Gi1/1/3                        down           down
Gi1/1/4                        down           down
Te1/1/1                        down           down
Te1/1/2                        down           down
Te1/1/3                        down           down
Te1/1/4                        down           down
Te1/1/5                        down           down
Te1/1/6                        down           down
Te1/1/7                        down           down
Te1/1/8                        down           down
Fo1/1/1                        down           down
Fo1/1/2                        down           down
Gi2/1/1                        down           down
Gi2/1/2                        down           down
Gi2/1/3                        down           down
Gi2/1/4                        down           down
Te2/1/1                        down           down
Te2/1/2                        down           down
Te2/1/3                        down           down
Te2/1/4                        down           down
Te2/1/5                        down           down
Te2/1/6                        down           down
Te2/1/7                        down           down
Te2/1/8                        down           down
Fo2/1/1                        down           down
Fo2/1/2                        down           down
Gi3/1/1                        down           down
Gi3/1/2                        down           down
Gi3/1/3                        down           down
Gi3/1/4                        down           down
Te3/1/1                        down           down
Te3/1/2                        down           down
Te3/1/3                        down           down
Te3/1/4                        down           down
Te3/1/5                        down           down
Te3/1/6                        down           down
Te3/1/7                        down           down
Te3/1/8                        down           down
Fo3/1/1                        down           down
Fo3/1/2                        down           down

I dont seem to find any documentation that explains this kind of behaviour. Maybe we are the first ones to deploy a stack with different NM configurations...

Thanks for having a look at this. Answers highly appreciated.

[Leo Laohoo]

This means someone has pre-provisioned the 3rd switch.  

This is a normal behaviour.  

Check the configuration for the following lines:  switch 3 provision <MODEL number>

[mario.jost]

Here are the lines:

switch#show running-config | include provi
switch 1 provision ws-c3850-12x48u
switch 2 provision ws-c3850-12x48u
switch 3 provision ws-c3850-12x48u

Can i change something here to get rid of the 3/1/X ports?

[Leo Laohoo]

What is the output to the command "sh switch d"?

You want to get rid of the 3rd switch?  

Use the command "no switch 3 provision ws-c3850-12x48u" provision of the 3rd switch will go away.  

W

[mario.jost]

Hello Leo

There you go:

Switch/Stack Mac Address : 0076.86b5.XXX - Local Mac Address
Mac persistency wait time: Indefinite
                                             H/W   Current
Switch#   Role    Mac Address     Priority Version  State
------------------------------------------------------------
 1       Member   0076.86c7.XXX     1      V02      Ready               
 2       Standby  0076.86c6.XXX     1      V02     Ready               
*3       Active   0076.86b5.XXX    1      V02     Ready               



         Stack Port Status             Neighbors     
Switch#  Port 1     Port 2           Port 1   Port 2
--------------------------------------------------------
  1         OK         OK               2        3
  2         OK         OK               3        1
  3         OK         OK               1        2

I dont want to get rid of the 3rd switch. I'd like to get rid of all the interfaces of the unexistent network module on the 3rd switch. We had 3 3750X Switches before the 3850 and they did not show unexisting NM ports as far as i can remember. Maybe this is a normal behaviour for the 3850 models. It just seemed odd having non existing interfaces in the configuration.

[giovanni.muretto]

This article explains the odd behaviour of showing up the ports in CLI even though they should be disregarded. Strange choice by Cisco

3850: Understanding interface configuration on NM modules - Cisco Community