Arista Warrior

Chapter 22. VM Tracer

Working in a large scale multitenant data center can mean a network with hundreds or even thousands of virtual machines. VLANs may be added, moved, or deleted 50 times a day in such an environment. Those VLANs need to be added and removed from edge switches by networking personnel who need to work closely with the VM teams. In my experience, this is often a time consuming task because of the high number of clients in a large multitenant environment. The Virtual Machine (VM) guys get annoyed when they have to wait for network changes, and the network team gets annoyed having to do boring work like adding and removing VLANs from trunk ports all day.

Enter VM Tracer. VM Tracer can be given a range of VLANs with which it can add, change, and remove without human interaction. The range of VLANs is communicated to the VM teams, and when they bring up a new VM, they choose one from the pool. When they configure the VLAN on the virtual switch, VM Tracer senses this change. It then adds the VLAN to the Arista switch, provisions the network port connected to the VM for the new VLAN, and the network team didn’t have to lift a finger. If the VM team decides to later remove the VLAN, the switch will automatically remove it from the server’s trunk port, and remove it if it is no longer used elsewhere on the switch.

Note

To be completely accurate, VM Tracer doesn’t sense anything. VM Tracer takes advantage of the application programing interface (API) provided by VMware in order ...