Enhanced VPC Dual Home Actual link speed?

[Aaron_un]

benefits of Enhanced VPC Dual Home of 5Ks and 2Ks includes redundancy and port channel across the FEXes, but I have a question specifically on the bandwidth speed...

if you look at this topology, which all the black links are 40Gb/s QSFP-SR4

is the speed of going from Point A to Point B in this fabric model(Enhanced Dual Homed VPC) 160Gb/s or 80Gb/s? in other word are we using all the 4 uplinks simultaneously and the 5k interchassis links to reach to point B? and that means 80%(128Gb/s), 90%(144Gb/s) or close to 100% link utilization speed?

and the last question(different question) if I have VLANs I don't need to use GLBP since the traffic is distributed on fabrics even at the layer 2 level and not just when it reaches the gateways I presume, so HSRP can achieve the same on fabrics?

[Dawei]

For Q1,

I assume Point B is an orphan port or a layer3 link, the answer is YES. To N2K, the uplink is a port-channel, so the traffic will be hash to those ports. Half of the packets are hashed to the left N5K and then forwarded to the right N5K via peer-link to point B.

For Q2,

In vPC environment, both HSRP active and standby are forward the traffic, NO GLBP required, and just HSRP and VRRP can be used.

[Sergiu.Daniluk]

One thing which I would like to add on top of what Dawei mentioned: the configured load balancing algorithm is also very important to ensure a fair distribution of traffic. For more details about it I would suggest to read this: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5600/sw/interfaces/7x/b_5600_Interfaces_Config_Guide_Release_7x/config_port_channels.html#con_1207090

Stay safe,

Sergiu