Adding servers to VPC domain

[CiscoPurpleBelt]

So if I have 2x Nexus switches joined to a VPC domain 1 and connect a server to both of these switches, would I configured the ports on the switch for the servers to be in another port-channel and another VPC domain let's say vpc 2. These configs look correct:

conf t
int e1/1-2
channel-group 2 mode active
int port-channel 2
vpc domain 2

[chrihussey]

If i understand you correctly, it shouldn't be necessary to create a new vPC domain. You should be able to simply create another port channel in the same vPC domain.

!

conf t
int e1/1-2
channel-group 2 mode active
int port-channel 2
vpc 2

!

Hope this helps

[Reza Sharifi · Accepted solution]

You only need one vPC domain. If your server connects to both switches, you need to put both links in a Portchannel and a vPC.  

If your main vPC is vPC 10, you can put the server in vPC 2, but no need for keyword "domain".

Example:

conf t
int e1/1-2
channel-group 2 mode active 
int port-channel 2
vpc  2

HTH

[CiscoPurpleBelt]

Is it necessary to join all the ports for the server to VPC? So far I just did the 2 ports I was referring to.

[CiscoPurpleBelt]

Actually when I do the configs you guys stated, I still get:

switch 1# sh interface port-channel 11                                         

port-channel11 is down (No operational members) 

Any idea why?

[Reza Sharifi]

Can you post Po11 config from both switches?

both switches need to have the same exact config

"sh run int po11" from both switches

"sh port-ch summ" from both switches

also, show the physical interfaces belonging to po11 from both switches

example:

sh run int ex/x 

HTH

[CiscoPurpleBelt]

Actually the port-channel is up now. Configs are just as noted above.

Is it necessary to join all server ports under a vpc X?

[Reza Sharifi]

Is it necessary to join all server ports under a vpc X?

Only if the server connects to both Nexus switches and also both Nexus switches vPVed together.

HTH

[CiscoPurpleBelt]

Ok thanks. Also, should the two peer-link port-channel between the two VPC peer switches be equally sharing the traffic load as "traffic summary" shows traffic only going through 1 of the ports?

[Reza Sharifi]

Ok thanks. Also, should the two peer-link port-channel between the two VPC peer switches be equally sharing the traffic load as "traffic summary" shows traffic only going through 1 of the ports?

So, it depends. If for example the sharing is based on source/destination MAC address and all traffic is sourcing from one MAC address than that one MAC address will only use one of the links. If there is a second device with a different MAC address, that second device should use the second link in the PO.

Here is a good link on understanding how load sharing works with PO. 

https://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/12023-4.html

HTH

[CiscoPurpleBelt]

Ok so yes the server is connected to both Nexus switches in a VPC domain but the actual ports on the switch that connect to the servers are not configured with VPC, but everything is working fine except for one issue with two interfaces on the server which are connected to ports 1 and 2 on both switches. It is only these 2 ports I tried configuring under a seperate port-channel and with a vpc x config, however if I do a LACP port-channel it goes down, if I just do regular port-channel it will be up, however with both instances, pings to the server host interfaces will drop sometimes.

[chrihussey]

So the VLAN needs to be in the vPC domain and allowed across the peer link. If not, you cannot create a port channel from the server to both Nexus switches.

Hope this helps

[CiscoPurpleBelt]

So the VLAN needs to be in the vPC domain and allowed across the peer link. If not, you cannot create a port channel from the server to both Nexus switches.

Yes so the switches are vPC Domain 1and under the server interfaces I configured "vPc 2" and "port-channel 2 active or just port-channel 2".

Peer-link is not pruned and allowing all Vlans. The port-channel is still down with any of these configs.

I think the problem is with the server side and also the fact of them being non-Cisco servers - NetAp.

If I don't have a port-channel and vpc 2 on the server port interfaces on the switch it seems to work but just have packet loss from pings every so often. I will also add the "peer-switch" command under VPC domain config.

Any suggestions what else I should check or do if any?

Any idea what may be wrong?

[chrihussey]

Do you have other vPCs operating or is this the only one?

Can you provide the vPC domain, port channel and port configs as well as identify the Nexus platform?

Thanks

[CiscoPurpleBelt]

Correct there are no other VPC on the ports just this.

Same on both switches except:

vpc domain 1                                                                    

  role priority 100 (same for both switches)                                                            

  peer-keepalive destination 172.168.1.1 source 172.168.1.2 vrf vpc-keepalive   

  dual-active exclude interface-vlan 5                                     

  peer-gateway                                                                  

  auto-recovery                                                                 

interface port-channel1                                                        

  vpc peer-link         

-----------

SVI configs

Same on both switches except where noted:

interface Vlan2                                                               

  description ServerHost                                                      

  no shutdown                                                                   

  no ip redirects                                                               

  ip address 172.168.2.2/24                                                   

  hsrp 2                                                                      

    preempt                                                                     

    priority 105 (priority default on Switch 2)                                                                

    ip 172.16.2.1

---------------

Same on both switches except

interface Ethernet1/45 and 46                                                           

  description vPC Peer-Link                                                     

  switchport mode trunk                                                         

  channel-group 1 mode active                                                  

  no shutdown   

-------------------------

Interfaces for server ports:

interface Ethernet1/1 and 2                                                          

  speed 1000                                                                    

  description ServerHost                                                

  switchport mode trunk                                                         

  switchport trunk allowed vlan 2

 switchport trunk native vlan 12                                             

  spanning-tree port type edge trunk                                            

  no shutdown 

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