Cisco 3850-48XS uplink to two Nexus switches

[timothy_MTS]

Hello everyone,

I was working on a project to setup an unused switch I found from the storeroom. It was being used before but now I have just wipe the configurations by "write erase" and I have also removed the vlan.dat. I have also updated the ios into 16.12.11

I believed that it was configured with another same switch as "stacked" before. So now, I have also removed the "stackwise-virtual link 1" on the 4 x FortyGigabitEthernet. I also removed the stackwise-virtual away.

But one thing I found in the show interface status and compare to the show run, there are different ports showing below.

show run (some output omitted)

!
interface TenGigabitEthernet1/0/47
!
interface TenGigabitEthernet1/0/48
!
interface TenGigabitEthernet1/1/1
!
interface TenGigabitEthernet1/1/2
!
interface TenGigabitEthernet1/1/3
!
interface TenGigabitEthernet1/1/4
!
interface TenGigabitEthernet1/1/5
!
interface TenGigabitEthernet1/1/6
!
interface TenGigabitEthernet1/1/7
!

show interface status

Te1/0/46 notconnect 1 auto auto unknown
Te1/0/47 notconnect 1 auto auto unknown
Te1/0/48 notconnect 1 auto auto unknown
Fo1/1/1 notconnect 1 auto auto unknown
Fo1/1/2 notconnect 1 auto auto unknown
Fo1/1/3 notconnect 1 auto auto unknown
Fo1/1/4 notconnect 1 auto auto unknown

There are around 16 ports of TenGigabitEthernet1/1/x while I don't see it from the hardware itself.

I eventually would like to trunk the 1 or 2 ports to my two existing Nexus switches. So, can I use those FortyGigabit ports to connect uplinks?

Cheers,

Timothy

[DanielP211]

Hello!

Did you do a factory reset? The ports te1/1/x are shown because of the use of a breakout cable. 

You can definatly use the Fo ports for connections to nexus. I would suggest using 2x Fo ports with LACP on the side of Catalyst and VPC on the side of nexus.

If you need any further help, please write.

BR

[timothy_MTS]

I didn't factory reset this switch. So do I need to do it?

I see. Will do the 2x Fo and form the PortChannel for that. Very great suggestion.

Cheers,

Timothy

[Reza Sharifi]

Hi,

The ports are lining up correctly. You have 48 ports of 10Gig SFP (1/0/1–1/0/48) and 4 ports of 40Gig, which are used for uplinks (fo1/1/1-1/1/4).

So, you should be able to connect a couple of these 40 Gigs to another switch that has the same type of port.

See table-19 in this link

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-3850-series-switches/datasheet_c78-720918.html

HTH

[timothy_MTS]

Yes. Thanks. I think according to DanielP's explain. That breakout cable on Te1/1/x, so we got 4 x FortyG ports, and each cable can split into 4 (each one is 10G), which is 4 x 4 = 16 ports, and exactly the number I have in the show running config. Te1/1/1 - Te1/1/16.

Thanks for the Help everyone.

Cheers,

Timothy