tcp messages
Vipul Ramani
linux2000in at gmail.com
Sat Jun 18 07:15:31 UTC 2005
hi Smith,
This is problem someone is running some sort of "tar-pit" system that is
designed to keep sockets in a bad state and run you out of kernel memory.
RFC793 describes the correct behaviors here:
The mechanisms provided allow a TCP to advertise a large window and to
subsequently advertise a much smaller window without having accepted that
much data. This, so called "shrinking the window," is
strongly discouraged. The robustness principle dictates that TCPs will not
shrink the window themselves, but will be prepared for such behavior on the
part of other TCPs.
The sending TCP must be prepared to accept from the user and send at least
one octet of new data even if the send window is zero. The sending TCP must
regularly retransmit to the receiving TCP even when
the window is zero. Two minutes is recommended for the retransmission
interval when the window is zero. This retransmission is essential to
guarantee that when either TCP has a
zero window the re-opening of the window will be reliably reported to the
other.
When the receiving TCP has a zero window and a segment arrives it must still
send an acknowledgment showing its next expected sequence number and current
window (zero).
V
On 6/6/05, DBSMITH at ohiohealth.com <DBSMITH at ohiohealth.com> wrote:
> Has anyone seen or know what these messages from dmesg are? Is there
> something that needs adjusted...aka window size?
>
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/35691<http://172.25.131.224:515/35691>shrinks window
> 4136994921:
> 4136996381. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/35696<http://172.25.131.224:515/35696>shrinks window
> 4169121581:
> 4169123041. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/35696<http://172.25.131.224:515/35696>shrinks window
> 4169121581:
> 4169123041. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/35697<http://172.25.131.224:515/35697>shrinks window
> 4174644883:
> 4174646343. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/35697<http://172.25.131.224:515/35697>shrinks window
> 4174669703:
> 4174671163. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/35697<http://172.25.131.224:515/35697>shrinks window
> 4174669703:
> 4174671163. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/38385<http://172.25.131.224:515/38385>shrinks window
> 1327521259:
> 1327522719. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/38385<http://172.25.131.224:515/38385>shrinks window
> 1327521259:
> 1327522719. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/38385<http://172.25.131.224:515/38385>shrinks window
> 1327532939:
> 1327534399. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/38388<http://172.25.131.224:515/38388>shrinks window
> 1347341800:
> 1347343260. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/38388<http://172.25.131.224:515/38388>shrinks window
> 1347352020:
> 1347353480. Repaired.
>
> TCP: Treason uncloaked! Peer 172.25.131.224:515/38388<http://172.25.131.224:515/38388>shrinks window
> 1347352020:
> 1347353480. Repaired.
>
>
> Derek B. Smith
> OhioHealth IT
> UNIX / TSM / EDM Teams
> 614-566-4145
>
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--
Vipul Ramani
linux2000in at gmail.com
linux2000in at yahoo.com
~~~~~We Know HOW NetWorkS ~~~~~
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