tcp ports ftp hangs in CLOSE_WAIT state with NMAP scanner - VxWorks
This is a discussion on tcp ports ftp hangs in CLOSE_WAIT state with NMAP scanner - VxWorks ; I have been using NMAP to scan all the open ports on my equipment
which runs VxWorks Version 5.3.1. The scanner some times causes hung
CLOSE_WAITS on the FTP port 21.
Eventually after 8 such CLOSE_WAIT connections, FTP server hangs.
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tcp ports ftp hangs in CLOSE_WAIT state with NMAP scanner
I have been using NMAP to scan all the open ports on my equipment
which runs VxWorks Version 5.3.1. The scanner some times causes hung
CLOSE_WAITS on the FTP port 21.
Eventually after 8 such CLOSE_WAIT connections, FTP server hangs.
I came across this posting:
http://groups.google.com/group/comp....7a1f9ffd8b886c
I'm seeing the same problem with my FTP server too. Whenever I run
NMAP to
scan the ports, my FTP server hangs with 8 connections in CLOSE_WAIT
state.
I could not find the fix for this problem.
If you have come across the same problem or know the fix for this
problem please let me know.
Thanks in advance.
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Re: tcp ports ftp hangs in CLOSE_WAIT state with NMAP scanner
On 9 Mar 2007, pawansun@gmail.com wrote:
> I'm seeing the same problem with my FTP server too. Whenever I run
> NMAP to scan the ports, my FTP server hangs with 8 connections in
> CLOSE_WAIT state.
You can reproduce the same thing on Linux, etc. However the amount of
connections would likely be higher. If NMAP (or anything) cause a
hanging CLOSE state, the TCP rfc say that this should remain in the
CLOSE_WAIT state for six hours or something insane like that.
You can increase the amount of sockets available. There might also be
a "CLOSE_WAIT" timer variable that can be changed to not wait for the
full close handshaking. I think that Windows might also perform a
truncated CLOSE sequence.
fwiw,
Bill Pringlemeir.
--
My cousin is an agoraphobic homosexual, which makes it kind of hard
for him to come out of the closet. - Bill Kelly
vxWorks FAQ, "http://www.xs4all.nl/~borkhuis/vxworks/vxworks.html"
