Final answer:
App-ID, a technology used by Palo Alto Networks firewalls, labels unknown traffic with specific labels like unknown-tcp, unknown-udp, or unknown-p2p, corresponding to TCP, UDP, or P2P traffic types. Administrators often investigate these labels further to maintain network security.
Step-by-step explanation:
The common labels used by App-ID to label traffic when the application is unknown are quite specific. Palo Alto Networks firewalls use App-ID technology to classify the traffic on the network. When App-ID is unable to identify the specific application, the traffic is typically categorized under labels such as unknown-tcp, unknown-udp, or unknown-p2p. Each label corresponds to the type of traffic: TCP (Transmission Control Protocol), UDP (User Datagram Protocol), or P2P (peer-to-peer) respectively. Additionally, there might be a generic unknown label used for traffic that does not fit the specific sub-categories of TCP, UDP, or P2P.
For an administrator, these labels serve as an indicator that an application was not recognized definitively by the firewall. It could prompt further investigation, such as determining whether the traffic is legitimate or potentially malicious. Understanding App-ID's ability to classify traffic helps maintain network security and efficiency.