vPC from 6800 to N9K

[Network Pro]

Hi

is it possible to run vPC from 1 x N9k to 2 x Core 6800IA

Core 1 (6800) ---VSS-----  Core 2 (6800 

   |                                                    |

   |___________N9k____________|

                       vPC?

Thanks

[Reza Sharifi]

Hi,

Yes, but there is no need for a vPC since you only have one N9k switch. You just need a regular Portchannel.

HTH

[Network Pro]

Thanks for responding but since there is vss between two 6800 how is it possible to vpc n9k? Remember there are 2 x 6800 cores and 1 n9k. I know vice Versa is possible but not this?

if possible what's the config?

[Reza Sharifi]

Hi,

If the 6800s are configured as VSS, they are logically one switch.  So, think of connecting one switch to one switch. As for config, its simple Portchannel config:

Here is an example: with

interface 1/1/3 and 2/1/3 as just examples

interface TenGigabitEthernet1/1/3
switchport trunk allowed vlan xxx
switchport mode trunk
channel-group 7 mode passive

interface TenGigabitEthernet2/1/3
switchport trunk allowed vlan xxx
switchport mode trunk
channel-group 7 mode passive

!
interface Port-channel7
switchport trunk allowed vlan xxx
switchport mode trunk

The same config on the nexus side with whatever ports you are planning to use.

HTH

[Network Pro]

Yes I understand this, but vPC does not come into play? I have been asked to do vPC but my understanding its not needed and NOT POSSIBLE. is this right ?

[Network Pro]

let me ask you this question

Is vPC possible from 

between two cores 6800(VSS) between them and to 2 x N9k (Downstream switches - layer 2) running vPC between them?

[Reza Sharifi]

According to your first post, you only have one Nexus 9k.  If that is the case then you don't need vPC.  If you have 2 9ks than you can configure vPC between the 9ks as well as 9ks and VSS.

HTH 

[Network Pro]

lets go with 2 x 9ks

so the cores are going to be 6800 with VSS and downstream switch is going to be N9k with vPC - how will this work ? should the n9k be Layer 3 ?

how will the config work ?

[Reza Sharifi]

Have a look at the this doc for best practice and configs.

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/interfaces/configuration/guide/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide_chapter_0111.html

HTH

[Network Pro]

seen this but the bit i am unclear about is the N9K communicating with 6800 on VSS

so lets look at the section below N9K - if I attach a switch or dual homed server to both Nexus and vPC between 2 x N9K then it will work which is fine but how is the connection between n9k and 6800 look like ? port channel or vPC ?

[Reza Sharifi]

Between the 9ks and 6800 VSS, you can just use layer-3 Portchannels.

for example:

nk9-a connects to both 6800 chassis using Portchannel 10 and 

nk9-b connects to both 6800 chassis using Portchannel 20.

HTH

[Network Pro]

should this be only layer 3 port-channels? issue i have is only 1 link from Core (6800) to each N9k - will ths work ?

so 

6800-----VSS----------6800

|                                 |

|                                 |

N9k1-------vPC-------N9k2

|                                  |

|----------server----------|

            (dual homed)

[Reza Sharifi]

To do this correctly, you need 4 links between VSS and the 9ks.  I have not tested this will only 2 links and not sure if it works.

HTH

[Network Pro]

i am thinking of using switched links between 6800 and N9k - let me know if you see any issues?