Networking

Using Packet Capture in the Public Cloud

By Keith Townsend

Packet capture is normally a tool of last resort in the private data center, but some organizations may want to consider it as a first stop in public cloud. Read on to see why packet capture and analysis tools are helpful in public cloud operations and migration.

Keith Townsend writes, “One of the appeals of infrastructure-as-a-service (IaaS) offerings is that the complexity of the physical underlay is abstracted away. While the complexity is abstracted, the fundamentals of computer science don’t disappear. Abstracted technology still breaks and needs troubleshooting. Because of this, the packet capture and analysis tools become arguably more useful in public cloud operations and migration.

“Here are three scenarios where you may find packet capture use in the public cloud.

“1. Detect non-supported applications. Public cloud networking is an abstraction of physical networking. From the perspective of the OS and application, all the services look similar to a physical network. The OS has a network adapter that allows the binding of protocols from TCP/IP to IPX/SPX. The major cloud providers only support TCP and UDP IP packets. Most modern applications mainly rely on these transport protocols, but there are caveats.

“One such caveat is broadcast- or multicast-based use cases. Cloud provider networks drop all broadcast and multicast traffic. If an application requires either technique, then you can expect a loss in functionality. Packet capture and analysis help to determine if there’s a reliance on multicast in an application. A typical architecture that requires multicast are applications that discover peers to form a cluster, or video broadcast solutions.”

Read on for two more scenarios where you may find packet capture helpful in the public cloud.