vPC Cisco Nexus 3048 to Cisco 3850

[johnlloyd_13]

hi,

i can't seem to get vPC trunks working between nexus 3K and 3850 switch. 3850 gives a log that LACP is not enabled on remote nexus 3k even though show port-channel summary it show LACP.

the 3850 will show ports 23 and 24 as UP then will show STP log/block and put them in err-disable. i tried to hard code both ends as 1000/full and tried different trunk mode combinations: active/active, on/on, active/passive but still failed.

not sure if this is a nexus code bug. does nexus need to be on the same code? core switch 1 runs version 6.0(2)U4(1) and core switch 2 runs 6.0(2)U3(7). can anyone advise if there's a better approach on this?

3850

*Mar 22 08:37:06.596: %EC-5-L3DONTBNDL2: Gi1/0/23 suspended: LACP currently not enabled on the remote port.
*Mar 22 08:37:15.497: %EC-5-L3DONTBNDL2: Gi1/0/24 suspended: LACP currently not enabled on the remote port.

Gi1/0/23  ### Trunk suspended    trunk      a-full a-1000 10/100/1000BaseTX
Gi1/0/24  ### Trunk suspended    trunk      a-full a-1000 10/100/1000BaseTX
Po102     ### vPC   notconnect   unassigned   auto   auto

interface GigabitEthernet1/0/23
 switchport mode trunk
 channel-group 101 mode active

interface GigabitEthernet1/0/24
 switchport mode trunk
 channel-group 101 mode active

interface Port-channel101
 switchport mode trunk

nexus 3K
cisco Nexus 3048 Chassis ("48x1GE + 4x10G Supervisor")

interface Ethernet1/19
  switchport mode trunk
  spanning-tree port type normal
  channel-group 101

interface port-channel101
  switchport mode trunk
  spanning-tree port type normal
  vpc 101

[Reza Sharifi]

Hi,

Is vPC configured correctly between the Nexus switches?

What is the output of "sh vpc"?

Also, vPC will work fine if you don't have the same OS on both Nexus but it usually is a good idea to keep them the same.

Can you remove "spanning-tree port type normal" from the Nexus and test again?

Also, can you post the full config from all devices? 

HTH

[johnlloyd_13]

hi reza,

can't give the show vpc right now. this is a new setup and remote tech is not online yet to give me OOB console. what keyword or particular output should i look out for?

noted on the nexus code. i plan to upgrade both nexus 3k to same code.

is this the correct way to upgrade nexus?

# install all kickstart bootflash:///n3000-uk9-kickstart.6.x.bin system bootflash:///n3000-uk9.6.x.bin

or type below and then reload?

boot kickstart bootflash:/n3000-uk9-kickstart.6.x.bin
boot system bootflash:/n3000-uk9.6.x.bin

is the vpc domain number '101' will cause STP issue/err-disable when i use same number port channel 101?

core 1

vpc domain 101
  peer-keepalive destination 10.10.21.254 source 10.10.21.253
  peer-switch

core 2

vpc domain 101
  peer-keepalive destination 10.10.21.253 source 10.10.21.254
  peer-switch

[Reza Sharifi]

Hi John,

vPC number should not matter. So, vPC domain 101 should be fine.

As for the upgrade you always want to use the "install all" command.

So, the command should look something like this. This command is not for you switch model but it should work the same way.  Also, in the command, you include both kickstart and system images. 

install all impact kickstart bootflash:n6000-uk9-kickstart.7.1.4.N1.1.bin system bootflash:n6000-uk9.7.1.4.N1.1.bin

Link:

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus6000/sw/upgrade/714_N1_1/n6000_upgrade_downgrade_714_n1_1.html#53613

Again this is for 6000 series but the commands should be the same just different os for the 3000 series.

HTH

[Reza Sharifi]

John,

No problem. You can provide the output tomorrow. I have to go to sleep soon :-)

I look at it tomorrow morning.

Reza

[johnlloyd_13]

hi reza,

just one more thing, i should patch a cross-connect between management0 interface between nexus 3k? this if for the vpc keepalive right?

[Reza Sharifi · Accepted solution]

Hi John,

Yes, you can use mgmt0 for vPC keep-alive. Best practice is to connect both mgmt interfaces to a third switch and put them in the same vlan.

see figure-3 in this link:

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-5000-series-switches/configuration_guide_c07-543563.html

HTH

[johnlloyd_13]

hi reza,

thanks! i think this is the missing piece.

i'll ask the tech to patch the x-connect cable and fix vpc first.

[johnlloyd_13]

reza,

as suspected, it was a vpc peer-link issue. 3850 uplinks to nexus 3k are now up and stable/no err-disable. thanks again!

# sh vpc

Legend:
                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                     : 1   
Peer status                       : peer adjacency formed ok      
vPC keep-alive status             : peer is alive                 
Configuration consistency status  : success
Per-vlan consistency status       : success                       
Type-2 consistency status         : success
vPC role                          : primary                       
Number of vPCs configured         : 6   
Peer Gateway                      : Disabled
Dual-active excluded VLANs        : -
Graceful Consistency Check        : Enabled
Auto-recovery status              : Disabled

vPC Peer-link status
---------------------------------------------------------------------
id   Port   Status Active vlans    
--   ----   ------ --------------------------------------------------
1    Po12   up     1,100                                                     

vPC status
----------------------------------------------------------------------------
id     Port        Status Consistency Reason                     Active vlans
------ ----------- ------ ----------- -------------------------- -----------
101    Po101       up     success     success                    1,100    
102    Po102       up     success     success                    1,100       
103    Po103       up     success     success                    1,100       
104    Po104       up     success     success                    1,100       
105    Po105       up     success     success                    1,100       
106    Po106       up     success     success                    1,100  

[Reza Sharifi]

Excellent John.

Glad to help and know it is all working for you now.

Thanks,

Reza