Flow Label

Network 20 bits IPv6 packet unverified

Labels a sequence of packets the sender wants handled as one flow.

Reading a capture

Has no IPv4 equivalent. Lets a router identify a flow without reaching into the transport header, which matters when that header is encrypted or sits behind an extension header chain.

Where it sits

IPv6 Packet > Flow Label

Open in the explorer — UDP over IPv6, in a QoS Data frame

Accuracy

Clause: RFC 8200 §3
Verified: Not verified against the standard. Treat this as a claim, not a fact.