802.11i Packet Formats
What is the packet format in IEEE 802.11i?
802.11i packet format extends standard 802.11 frames with security fields to support encryption and authentication.
How does 802.11i modify the MAC header?
It adds the Robust Security Network (RSN) information elements and security-related flags to the MAC header.
What security fields are included in 802.11i packet formats?
Fields for Key MIC, Sequence Number, and encrypted payload are included for confidentiality and integrity.
Does 802.11i support both data and management frame protection?
Yes, 802.11i includes mechanisms for protecting data frames and optionally management frames (PMF).
How are encryption headers incorporated into the frame?
Encryption headers like CCMP add extra fields after the MAC header and before the payload.
What is the role of the CCMP header in packet formats?
The CCMP header provides nonce and authentication data for AES encryption of the frame.
How does 802.11i handle fragmentation in secure packets?
Fragmentation headers are preserved and each fragment is individually encrypted and secured.
Are control frames changed by 802.11i?
Control frames remain mostly unchanged as they are not typically encrypted.
How is the MIC (Message Integrity Code) included in packets?
The MIC is appended to encrypted payloads to verify data integrity and authenticity.
What is the impact of 802.11i on frame size?
Additional security headers increase frame size slightly but ensure robust protection.
How does the frame format support key management exchanges?
Special frames like EAPOL use specific format extensions to carry key handshake information.
Does 802.11i frame format support Quality of Service (QoS)?
Yes, it is compatible with QoS extensions allowing prioritized secure traffic.
Are multicast and broadcast frames handled differently in packet format?
Group keys and encrypted payloads secure multicast and broadcast transmissions.
What elements ensure backward compatibility in 802.11i frames?
Legacy-compatible fields and versioning allow interoperability with older devices.
How are management frames optionally protected?
Protected Management Frames (PMF) add security elements to management frames without altering core structure.
What changes are made to the Frame Control field?
Flags in Frame Control indicate the presence of protected frames and security features.
How are replay counters included in packet formats?
Replay counters are embedded in security headers to prevent replay attacks.
Are there differences in packet format between TKIP and CCMP?
Yes, each encryption protocol defines specific headers and MIC structures within the frame.
How is integrity ensured across all packet fragments?
Each fragment includes its own MIC and encryption parameters to maintain security.
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