Nexus 7700 M3 100G Line Card Port channeling

[StevenKing1]

Hello everyone,

I'm in the middle of a design and was curious to find out what are everyone's thoughts about Nexus Chassis in the Campus. I'm asking this due to the fact that our building layouts have about 500 Switch stack uplink connections that need collecting to a Dist Switch and was considering to put the Nexus 7718 since it has that kind of port density and backplane capacity. Your thoughts?

Second part would be the over-subscription portion due to the sheer number of downstream links. I'm planning to put this particular card M3 100G for the Nexus Uplinks

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-7000-series-switches/datasheet-c78-738175.html

I wasn't able to find the limitation but is there a cap to how many interfaces that can be placed in a L3 Port channel? I'm hoping to bundle them together for management rather than rely on separate routed interfaces and ECMP.

Thank you all for your time 

[Reza Sharifi]

Hi,

So, you plan is use 100Gig uplinks from the access switches to the core or use breakout cables and use multiple 10Gigs.  With Nexus, you can bundle up to 16 ports in one Portchannel using LACP.

HTH

[StevenKing1]

Thanks for your reply

Perhaps this visual can help. I wanted to see if it was possible to add more links between the ASRs and the Nexus and bundle them together. So its up to 16 ports that I can do this with the M3 100G line cards? 

Oversubscription Ratios

[Reza Sharifi · Accepted solution]

Hi,

The 16 port per bundle only applies to Nexus platform. So, if you are connecting a Nexus to a different platform, that number goes down to 8 links per bundle.

Also, what is upstream from the ASRs?  Are you connecting to Internet? 

I am trying to understand your requirement and if you really need multiple 100Gig connections.

HTH

[StevenKing1]

Upstream from the ASRs are the MPLS mesh of 4 of ASRs (2 located in each data center). These would be the P routers

I'm designing something for the aviation industry, so the portion where it goes from Access Switch stack - Nexus - ASR is an example of one the buildings in the compound and there are multiple buildings that have this same setup ( with many switch stack closets around 500 number ). So I'll have to mind the oversubscription. You're thinking multiple 40G links would suffice?

[Reza Sharifi]

To better understand the requirement, it would help if you can get some sort of matrix of the current traffic pattern, bandwidth usage, type of applications, upstream/downstream link utilization, pick and off-pick hours bandwidth utilization. For this many equipments, I am sure they have monitoring systems that can provide this type of information. 

HTH

[StevenKing1]

Although I'd love to share that, this project is in the green field stage. Construction is being implemented and systems aren't in place yet. At this particular juncture, we are projecting networking devices in place based on quantities of data, video, voice outlets