From: me@sillymon.ch (Silvan Jegen)
To: kernelnewbies@lists.kernelnewbies.org
Subject: lots of connections in SYN_RECV state
Date: Thu, 06 Nov 2014 15:30:46 +0100 [thread overview]
Message-ID: <474e6128e9ee78a6e47d51dc776dc3fd@sillymon.ch> (raw)
In-Reply-To: <SNT153-W1098FF92FB3DD0EFE27BF899840@phx.gbl>
Hi
Am 2014-11-06 14:27, schrieb Puneet Agarwal:
> I have a couple of servers, for the past few days I am seeing lots of
> connections in SYN_RECV state in netstat commands output.
This *could* be the result of a SYN-flood attack on your server.
> Is there a solution to this problem?
The Wikipedia page mentions some countermeasures (if it indeed is an
attack and not a networking stack issue).
http://en.wikipedia.org/wiki/SYN_flood
Maybe you could check from which IP addresses these SYNs come from and
investigate why they do not answer to the SYN-ACK request of your
server.
Cheers,
Silvan
next prev parent reply other threads:[~2014-11-06 14:30 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-06 13:27 lots of connections in SYN_RECV state Puneet Agarwal
2014-11-06 14:30 ` Silvan Jegen [this message]
2014-11-06 15:15 ` Puneet Agarwal
2014-11-06 15:58 ` Silvan Jegen
2014-11-07 15:49 ` Dave Tian
2014-11-07 16:58 ` Valdis.Kletnieks at vt.edu
2014-11-07 23:48 ` Dave Tian
2014-11-07 17:41 ` Puneet Agarwal
2014-11-07 18:10 ` Valdis.Kletnieks at vt.edu
2014-11-08 2:05 ` Puneet Agarwal
-- strict thread matches above, loose matches on Subject: below --
2015-03-10 12:03 OpenStack - Libvirt+Xen CI overview Bob Ball
2015-03-16 15:09 ` OpenStack - Libvirt+Xen CI overview : anyone interested in a walk/through or presentation on how it works Lars Kurth
2015-03-16 18:00 ` OpenStack - Libvirt+Xen CI overview Konrad Rzeszutek Wilk
2015-03-17 12:52 ` Dario Faggioli
2015-03-17 11:14 ` George Dunlap
2015-03-17 14:22 ` Jim Fehlig
2015-03-17 15:51 ` Alvin Starr
2015-03-18 13:12 ` OpenStack - Libvirt+Xen CI overview : anyone interested in a walk/through or presentation on how it works Lars Kurth
2015-03-18 14:37 ` Wei Liu
2015-03-24 18:17 ` Lars Kurth
2015-03-25 10:08 ` Ian Campbell
2015-03-25 10:09 ` Bob Ball
2015-03-25 12:26 ` Alvin Starr
2015-04-22 10:03 ` Lars Kurth
2015-06-04 17:12 ` Bob Ball
2015-06-05 11:47 ` Lars Kurth
2015-06-08 12:52 ` Bob Ball
2015-06-10 14:25 ` Bob Ball
2015-06-15 16:26 ` Bob Ball
[not found] <10286402.11.1422626774586.JavaMail.kraghavendra@Raghavendra>
2015-01-30 14:08 ` Yocto-custom kernel build issue Raghavendra Kakarla
2015-01-30 16:34 ` Bruce Ashfield
2015-02-02 10:00 ` Raghavendra Kakarla
2015-02-03 12:40 ` yocto-custom-kernel issue Raghavendra Kakarla
2015-02-03 13:17 ` Sven Ebenfeld
2015-02-03 15:37 ` Bruce Ashfield
2015-02-05 8:56 ` MIPS32r2 little endian bsp Raghavendra Kakarla
2015-02-06 15:04 ` Mark Hatle
2015-02-10 8:17 ` Yocto-custom kernel build issue Raghavendra Kakarla
2015-02-10 11:00 ` Paul Eggleton
[not found] ` <2974616.30.1423571125144.JavaMail.kraghavendra@Raghavendra>
2015-02-10 13:36 ` Paul Eggleton
2015-02-11 4:55 ` Raghavendra Kakarla
2015-02-11 9:30 ` Paul Eggleton
2015-02-11 10:00 ` Raghavendra Kakarla
2015-03-03 5:41 ` SDK generation issue Raghavendra Kakarla
2015-03-03 9:37 ` Paul Eggleton
2015-03-03 10:26 ` Raghavendra Kakarla
2015-03-03 10:31 ` Paul Eggleton
2015-03-03 11:55 ` Raghavendra Kakarla
2015-03-03 12:10 ` Paul Eggleton
2015-03-03 12:17 ` Raghavendra Kakarla
2015-03-03 13:16 ` Paul Eggleton
2015-03-10 4:21 ` Difference b/w yocto kernels and normal linux.org kernels Raghavendra Kakarla
2015-03-10 4:33 ` Khem Raj
2015-03-10 4:45 ` Nicholas Krause
2015-03-13 8:14 ` Raghavendra Kakarla
2015-03-13 8:53 ` Paul Eggleton
2015-03-13 9:05 ` Albert K
2015-03-13 9:12 ` Paul Eggleton
2015-04-03 6:04 ` Raghavendra Kakarla
2015-03-03 17:55 ` SDK generation issue Jim Rafert
2014-12-12 8:10 UBIFS: Is it possible to get the compressed size of a file? markus.heininger
2014-12-17 6:22 ` hujianyang
2014-12-18 11:08 ` Aw: " markus.heininger
2015-02-02 9:33 ` Artem Bityutskiy
2015-02-02 9:33 ` Artem Bityutskiy
2015-02-03 5:45 ` Andreas Dilger
2015-02-03 5:45 ` Andreas Dilger
2015-02-03 9:07 ` Artem Bityutskiy
2015-02-03 9:07 ` Artem Bityutskiy
2015-02-28 7:31 ` hujianyang
2015-02-28 7:31 ` hujianyang
2015-03-26 14:19 ` David Sterba
2015-03-26 14:19 ` David Sterba
2012-03-19 20:59 Linking two recipes simran singh
2012-03-19 21:22 ` Richard Purdie
2012-03-19 21:33 ` simran singh
2012-03-19 21:39 ` Christopher Larson
2012-03-19 21:57 ` simran singh
2012-03-19 21:59 ` Christopher Larson
2012-03-19 22:10 ` simran singh
2012-03-19 22:54 ` Richard Purdie
2012-03-20 19:25 ` simran singh
2012-04-07 3:44 ` Khem Raj
2005-01-11 9:28 [U-Boot-Users] PCI, Ethernet, IXDP425 Ara Avanesyan
2005-01-11 22:40 ` Wolfgang Denk
2005-01-12 6:18 ` [U-Boot-Users] " Ara Avanesyan
2005-01-12 6:41 ` Rodel Miguel
2005-01-12 7:41 ` Ara Avanesyan
2005-01-12 8:08 ` Ing.Gianfranco Morandi
2005-01-12 9:01 ` Wolfgang Denk
2005-01-12 9:32 ` Ara Avanesyan
2005-01-12 10:13 ` Anders Larsen
2005-01-12 14:16 ` Wolfgang Denk
2005-01-12 14:16 ` Wolfgang Denk
2005-01-12 15:07 ` Ara Avanesyan
2003-11-12 17:23 [U-Boot-Users] [PATCH] fix the ARM memory layout Anders Larsen
2003-11-12 19:52 ` Kyle Harris
2003-11-13 9:14 ` Anders Larsen
2003-11-13 14:19 ` Kyle Harris
2003-11-21 3:52 ` Kyle Harris
2003-11-21 7:47 ` Anders Larsen
2003-11-21 8:13 ` Wolfgang Denk
2003-12-07 0:17 ` Wolfgang Denk
2003-12-07 17:03 ` Anders Larsen
2004-01-09 11:14 ` Anders Larsen
2004-02-08 19:36 ` Wolfgang Denk
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