1.1.e (vii) TCP Options

Although the section is really titled 1.1.e (vii) Options, we it is actually referring to TCP Options. Thus you should memorize these options, and thier purpose.


TCP Options:
Many options exist, but these are the only used ones:
End of options list = denotes the end of the TCP options, always comes at the end
NOP = padding to align options on 32 bit boundaries
Maximum segment size = Only used on SYN, hosts exchange their TCP MSS
Window scale = Only used on Syn, hosts determine how big their windows can be multiplied by
SACK PERMITTED = only used on syn to show that client is sack capable
Timestamp = timestamp host received this packet