Summary: New voices gather in the Packet Pushers virtual boardroom for a discussion of Cisco's layer 2 extension technology, Overlay Transport Virtualization (OTV). Ethan Banks hosts a recording of about two hours worth of content about OTV; this show is the first hour. Joining Ethan are first-time guests Jamie Caesar, Colby Glass and Ken Matlock. Jamie, Colby and Ken have all done real-world OTV deployments. Among the three, both the Cisco Nexus 7000 platform and ASR1000 platforms are represented. What's OTV and why do you care? OTV is a layer 2 extension technology aka data center interconnect (DCI). By L2 extension, we mean extending a VLAN from one data center into a different data center, when those data centers are separated by a layer 3 boundary. OTV is a tunneling overlay that encapsulates Ethernet frames so that they can cross the layer 3 area separating the 2 data centers. While simple in concept and fairly simple to deploy, OTV is rather complex behind the scenes, which is why this was a 2 hour discussion instead of 20 minute one. Here in part one, we cover the following high level topics. What is OTV, and what problems does it solve? OTV use-cases beyond vMotion. How latency introduced by long-distance DCI impacts applications. What hardware can you run OTV on? How does OTV compare to other L2 extensions? What sort of datagrams does OTV encapsulate? How many disparate data centers can OTV stitch together? OTV's fault-isolation mechanisms. How is spanning-tree handled in an OTV deployment? Is 2 OTV edge devices always an appropriate topology? OTV design considerations, hardware and licensing. OTV terminology. Can you run multiple overlays? How do OTV endpoints discover one another when using multicast? Unicast? LINKS Cisco OTV Home Page Cisco OTV White Papers (excellent resources)
