Nexus 7000 - 2000 setup --> how to connect servers

[Joris Deprouw]

Hi all,

We have a setup of 2 Nexus 7000 chassis and several fexes (N2K-C2248TP-1GE).

The fexes are connected through a port-channel to a single nexus 7000 (no vpc). (Fex 1 to Nexus 1, fex 2 to Nexus 2, fex 3 to nexus 1 etc).

Are there guidelines on how to connect a server to those fexes.

I can see several possible scenario's at our site. I have drawn some scenario's on a design.

Can anyone tell me if these are all possible? I can't find detailed information on which setup is possible and which is not. The goal is to have as much redundancy as we can.

When using scenario 1, do I configure an orphan port on the uplink to this server?

Thanks,

best Regards,

Joris

[Reza Sharifi]

Hi,

Currently, you can connect a FEX to only one 7K.  As for your sever connectivity options, have a look at this link for different scenarios.

look under Nexus 7000 topologies

http://jeremywaldrop.wordpress.com/2011/06/30/cisco-nexus-50007000-fex-topologies/

Alos, option 4 in your design seems to most redundant topology.

HTH

[Joris Deprouw]

Thanks Reza,

So it is possible to create a vpc to the server in scenario 4? Putting 2 ports in fex 1 and 2 ports in fex 2 in vpc. Although the fexes themselves can't be connected in vpc.

Is that correct?

Thanks,

Joris

[Reza Sharifi]

Hi,

I would put all the 4 ports connecting to both 2ks in the same Fex.  Remember, you also need vPC peer link and vPC keep alive between the 7ks.  I don't see these in your diagram currently.

HTH

[Joris Deprouw]

Hi,

The VPC peer link and keepalive is there, it's not on the drawing.

I would like to avoid putting all 4 ports on the same fex. the single fex would be a single point of failure.

I would like to create eg. Po1 on both nexusses with the member ports being the uplink to the server and then making them member of the same vpc.

Would that be a possibility?

Thanks,

Joris

[Reza Sharifi]

Hi Joirs,

Creating a vPC with 4 physical ports in it is not a single point of failure. If one physical link fails you have 3 more, if 2 fails, you have 2 more and so on.  

I would like to create eg. Po1 on both nexusses with the member ports being the uplink to the server and then making them member of the same vpc.

The one I also recommenced is one vPC/Po for all links.

HTH

[Steve Fuller]

Hi,

Sorry.... had to chip in

put all the 4 ports connecting to both 2ks in the same Fex

Reza. I think this is a typoe and that you meant put all the 4 ports connecting to both 2ks in the same vPC. If not Joris is correct that a single FEX is a single point of failure.

Otherwise I would agree with Reza, that option 4 looks to be the most resilient.

Regards

[Reza Sharifi]

Guys,

Sorry about that typo. I meant same vPC.

put all the 4 ports connecting to both 2ks in the same vPC

Reza

[Joris Deprouw]

Thanks Guys,

So the basic guideline is. Connect a server with multiple NIC's to different fexes.

When active-passive --> connect like access ports.

When NIC teaming --> use vPC over multiple fexes.

I would not use 2 active standard port-channels to 2 different fexes. I suppose you would have mac flapping in that case.

Best Regards,

Joris

[Reza Sharifi · Accepted solution]

Correct. multiple NICs to 2 different FEXes will you give you the most redundancy. Also one portchannel for all links connecting to both FEXes using vPC.

When active-passive --> connect like access ports.

Correct, you can do access or trunk if you have multiple vlans.

HTH

[Joris Deprouw]

Thanks guys,

[Reza Sharifi]

Joris,

If the answers were helpful to you, can you rate and mark the post as answered, so others can benefit from it.

Thanks