N7K vPC Configuration In Multi-VDC Environment

[zekebashi]

Hello, 

We have a production N7K(7009) with 4 VDCs. We are planning on deploying a second N7K(7009) for redundancy purposes. The primary N7K has the VDC_Core, VDC_Dist , VDC_DC1, and VDC_DC2. I am planning on connecting the two N7Ks using vPC and wasn't sure if I will have to connect each VDC on the primary chassis to the secondary chassis or just one VDC on the primary to another VDC on the secondary. Here's an example:

Scenario_01: Connecting a single VDC from each chassis using vPC 

N7K_01:                                  N7K_02: 

     VDC_Core ------- vPC--------    VDC_Core 

     VDC_Dist                                    VDC_Dist

     VDC_DC1                                   VDC_DC1

     VDC_DC2                                   VDC_DC2

Scenario_02: Connecting each VDC from each chassis using vPC 

N7K_01:                                  N7K_02: 

     VDC_Core  ------- vPC--------    VDC_Core 

     VDC_Dist    ------- vPC--------    VDC_Dist

     VDC_DC1   ------- vPC--------    VDC_DC1

     VDC_DC2   ------- vPC--------    VDC_DC2

Which approach is the correct one and why? 

Thanks in advance.

Best, ~zK

[ahmedshoaib]

Hi;

It's all about the network requirement. I will go with scenario 2 with 1 modification my Core_VDC will be completely L3. and all VDC will be connected with my core VDC on L3 links.

In Dist_VDC, DC1_VDC & DC2_VDC will be configured as separate vPC domain so, I can create multi-chassis etherchannel to utilize full bandwidth and redundancy.

Thanks & Best regards; 

[zekebashi]

Hello, 

Thanks for the input. The new design will be pretty similar to the 2nd scenario but will not be creating vPCs between all the VDCs. Only VDC_Core(1 & 2) and VDC_Dist (1 & 2) will be connected via vPC respectively. The current/production network only has VDC_Dist1 connected to VDC_Core1 via L3, so I will only connect VDC_Dist2 to both VDC_Core1 & VDC_Core2 via L3. Here's how I have designed it: 

     N7K_01:                                        N7K_02: 

     VDC_Core1  ------- vPC--------    VDC_Core2 

     VDC_Dist1   ------- vPC--------    VDC_Dist2

     VDC_Core1  -----2x10G --L3-------VDC_Dist1

     VDC_Core1  -----1x10G--L3--------VDC_Dist2

     VDC_Core2 -----1x10G-L3------VDC_Dist1

     VDC_Core2 -----2x10G-L3------VDC_Dist2

Feel free to comment. 

Best, ~zK 

[ahmedshoaib]

Hi;

The new design is OK just a single modification from VDC_Core (1&2) to VDC_Dist (1&2) 4x10 links are Ok no need to connect 6x10 G link. Run OSPF which will provide load balancing on all 4 links as a result you will get 40 G bandwidth b/w VDC_Core to VDC_Dist which is more then enough.

Thanks & Best regards;