Flag
Symbol
|
TCP
Flag
|
Flag
Meaning
|
.
|
Placeholder
|
If
the connection does not have a SYN, FIN, RESET, or PUSH
flag set, a placeholder will be found after the
destination port.
|
ack
|
ACK
|
This
flag is used generally to acknowledge the receipt of data
from the sender. This may be piggybacked with other flags.
|
F
|
FIN
|
This
flag indicates the sender's intention to gracefully
terminate the sending host's connection to the receiving
host.
|
P
|
PUSH
|
This
flag immediately "pushes" data from the sending
host to the receiving host's application software. There
is no waiting for the buffer to fill up.
|
R
|
RESET
|
This
flag indicates the sender's intention to immediately abort
the existing connection with the receiving host.
|
S
|
SYN
|
This
is a session establishment request, which is the first
part of any TCP connection.
|
urg
|
URGENT
|
This
flag indicates that there is "urgent" data that
should take precedence over other data. An example of this
is pressing Ctrl + C to abort an FTP download.
|