Книга: Iptables Tutorial 1.2.2
SCTP COOKIE ACK chunk
SCTP COOKIE ACK chunk
The COOKIE ACK chunk is used during the initialization of the connection and never anywhere else in the connection. It must precede all DATA and SACK chunks but may be sent in the same packet as the first of these packets.
Type - bit 0-7. Always set to 11 for this type.
Chunk flags - bit 8-15. Not used so far. Should always be set to 0 according to RFC 2960 - Stream Control Transmission Protocol. You should always watch out for this kind of specific behaviour stated by RFC's since it might change in the future, and hence break your firewalls etc. Just the same as happened with IP and ECN. See the SCTP Common and generic headers section for more information.
Length - bit 16-31. Should always be 4 (bytes) for this chunk.
- SCTP Generic header format
- SCTP Common and generic headers
- SCTP ABORT chunk
- SCTP COOKIE ACK chunk
- SCTP COOKIE ECHO chunk
- SCTP DATA chunk
- SCTP ERROR chunk
- SCTP HEARTBEAT chunk
- SCTP HEARTBEAT ACK chunk
- SCTP INIT chunk
- SCTP INIT ACK chunk
- SCTP SACK chunk
- SCTP SHUTDOWN chunk
- SCTP SHUTDOWN ACK chunk
- SCTP SHUTDOWN COMPLETE chunk