[AusNOG] Assistance with Cisco vPC configuration on 4 x Cisco Nexus 3000 switches

Mon Nov 26 14:19:49 EST 2018

Hi all,

With vPC on both pairs, all 4 links between the pairs can be aggregated
into a single port-channel like the one pictured below. Practically you're
going to setup two different vPC domains (vpc domain 1, vpc domain 2 for
example) on the two pairs (11,12) and (13,14). With a port-channel
configuration like the following example:

Assuming e1/1-2 are the downstream links (between pairs) and e1/10-11 are
the links between vPC peer switches

*# Setup vPC*
sw11# vpc domain 11 ; peer-keepalive destination <mgmt-ip sw12> ; int
e1/10-11 ; channel-group 1 mode active ; int po1 ; vpc peer-link ;
peer-switch ; peer-gateway
sw12# vcp domain 11 ; peer-keepalive destination <mgmt-ip sw11> ; int
e1/10-11 ; channel-group 1 mode active ; int po1 ; vpc peer-link ;
peer-switch ; peer-gateway

sw13# vpc domain 13 ; peer-keepalive destination <mgmt-ip sw14> ; int
e1/10-11 ; channel-group 1 mode active ; int po1 ; vpc peer-link ;
peer-switch ; peer-gateway
sw14# vpc domain 13 ; peer-keepalive destination <mgmt-ip sw13> ; int
e1/10-11 ; channel-group 1 mode active ; int po1 ; vpc peer-link ;
peer-switch ; peer-gateway

! Peer-switch will allow both vPC peers to propagate the same STP BPDU
information by sharing a vMAC
! Peer-gateway allows the partner to route on behalf of the other, this
gets around some non-RFC behavior seen in certain NAS vendors products when
using FHRP
! It's perfectly fine to use mgmt0 interfaces for the peer-keepalive, it's
a stream of UDP packets to src/dst port 3200. This link can go down with no
ill effect on vPC
! Note conventions for numbering of port-channels and domains is just for
example, use whatever numbering system works for you

*# Setup the port-channels*
sw11# int e1/1-2 ; channel-group 1314 mode active ; int po1314 ; vpc
sw12# int e1/1-2 ; channel-group 1314 mode active ; int po1314 ; vpc

sw13# int e1/1-2 ; channel-group 1112 mode active ; int po1112 ; vpc
sw14# int e1/1-2 ; channel-group 1112 mode active ; int po1112 ; vpc

[image: vpc.png]

Regards,
Jason.

On Mon, 26 Nov 2018 at 11:10, Ahad Aboss <ahad at swiftelnetworks.com> wrote:

> Radeck,
>
> To avoid blocked ports, you will need to configure your upstream links as
> follows;
>
> Built a port-channel from SW13 to SW11/12.
> Build a port-channel from SW14 to SW11/12.
>
> Physically, SW 11 and 12 looks as 2 x Switches but logically, SW 13 and 14
> treats SW11/12 as a single switch.
>
> I suggest using at least 2 x 10GE ports between SW13 & 14 as SFP's do fail
> from time to time.
> You can use MGM for peer link keep alive or a dedicated link.
>
> You can increase your port-channel capacity as your traffic grows.
>
> Ahad
>
> On Mon, Nov 26, 2018 at 10:16 AM Radek Tkaczyk <radek at tkaczyk.id.au>
> wrote:
>
>> Hi Guys,
>>
>>
>>
>> So from the feedback so far is that we should also link SW-13 and SW-14
>> directly – updated as below.
>>
>>
>>
>> The primary purpose for this design is to ensure redundancy across
>> switches, and to be able to provide approx. 50 x 10Gbps ports, and 50 x 1
>> Gbps ports – this also leaves heaps of room for growth as well.
>>
>>
>>
>> Still looking for someone to go over the config with, so if you are
>> interested (paid gig) please let me know.
>>
>>
>>
>>
>>
>>
>>
>> Thanks
>>
>>
>>
>> Radek
>>
>>
>>
>> *From:* AusNOG [mailto:ausnog-bounces at lists.ausnog.net] *On Behalf Of *Radek
>> Tkaczyk
>> *Sent:* Sunday, 25 November 2018 4:34 PM
>> *To:* Jacob Taylor <me at jacobtaylor.id.au>
>> *Cc:* <ausnog at lists.ausnog.net> <ausnog at lists.ausnog.net>
>> *Subject:* Re: [AusNOG] Assistance with Cisco vPC configuration on 4 x
>> Cisco Nexus 3000 switches
>>
>>
>>
>> Hi Jake,
>>
>>
>>
>> That’s something that I wanted to check if it was needed/recommended.
>>
>>
>>
>> Can certainly put it in if it will help achieve better performance and
>> redundancy
>>
>> Thanks
>>
>>
>>
>> Radek
>>
>>
>> On 25 Nov 2018, at 4:26 pm, Jacob Taylor <me at jacobtaylor.id.au> wrote:
>>
>> Hi Radek,
>>
>>
>>
>> Not personally familiar with vPC, more so Arista MLAG and Juniper MC-AE.
>>
>>
>>
>> In the diagram there isn’t a peer link between 13 & 14 - is that a
>> mistake in the diagram or the actual design?
>>
>>
>>
>> If you intend to build 2x20G bonds to two standalone nexus switches,
>> that’ll work fine.
>>
>>
>>
>> If you are trying to achieve a 40G bowtie between the two pairs I’m
>> fairly certain that won’t work (unless Cisco has some special black magic
>> to transport signalling/MAC synchronisation over the bond itself).
>>
>>
>>
>> Cheers,
>>
>> Jake
>>
>>
>>
>>
>>
>>
>> On 25 Nov 2018, at 15:04, Radek Tkaczyk <radek at tkaczyk.id.au> wrote:
>>
>> Hi Guys,
>>
>>
>>
>> I have a need to configure vPC on 4 x Cisco Nexus 3000 switches at one of
>> our data centres – a design that we will replicate to other data centres as
>> well.
>>
>>
>>
>> I think I have the config down pat, but I’d like someone with another
>> pair of eyes to go over it with me to ensure it’s 100% correct.
>>
>>
>>
>> Is there anyone who can give me a hand here with this configuration,
>> happy to pay for someone’s time to go over it to ensure we are doing this
>> correctly.
>>
>>
>>
>> The Physical setup that I’m looking for:
>>
>>
>>
>>
>>
>> <image001.png>
>>
>>
>>
>> Thanks
>>
>>
>>
>> Radek
>>
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>
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