| TCP option 6, Echo |
Description:
| Implementation | |
|---|---|
| Host | Obsolete. |
| Router | Obsolete. |
This option may be sent in any segment, but only if a TCP Echo option was received in a SYN segment for the connection.
| MAC header | IP header | TCP header | TCP option | Data |
TCP Option 6:
| 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Kind | Length | ||||||||||||||
| Info
::: |
|||||||||||||||
Kind. 8 bits. Set to 6.
Length. 8 bits. Set to 6.
Info. 32 bits.
Information that the receiving TCP may send
back in a subsequent TCP Echo Reply option.
Glossary:
RFCs:
[RFC 1072] TCP Extensions for Long-Delay Paths.