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Date:      Fri, 11 May 2012 16:15:48 -0600
From:      "Chad Leigh Shire.Net LLC" <chad@shire.net>
To:        Chuck Swiger <cswiger@mac.com>
Cc:        FreeBSD Mailing List <freebsd-questions@freebsd.org>
Subject:   Re: question on SYN_SENT
Message-ID:  <0A88B145-82C4-4167-AD13-829CCAC6298F@shire.net>
In-Reply-To: <4782C161-4B28-4276-9559-A54B711368F1@mac.com>
References:  <D8AF0C20-E2C0-44A4-89DF-B614F3DBBFF6@shire.net> <4782C161-4B28-4276-9559-A54B711368F1@mac.com>

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On May 11, 2012, at 4:08 PM, Chuck Swiger wrote:

> On May 11, 2012, at 2:09 PM, Chad Leigh Shire.Net LLC wrote:
>> it is my understanding that SYN_SENT is when MY SIDE sends out a =
request and is awaiting a reply?
>=20
> That's right.
>=20
>> One of the jails we run for a customer had hundreds (if not =
thousands) of attempts to connect from the 147. address you see below.   =
It was exhausting resources so that new tcp connections could not be =
made until some closed.
>=20
> You have/had your jail opening connections to the webserver at IP =
147.237.76.155, not that IP trying to connect to you.
>=20
>> I added that address to a "pf" block statement to stop it but now we =
get a rolling connections in a "netstat -a" as show below (host. being a =
generic name used in place of actual host on our side).   I am wondering =
if this shows something on our side trying to connect out?  That is what =
it appears to me to be, which does not make sense.
>>=20
>>=20
>> tcp4       0      0 host.52562         147.237.76.155.http    =
SYN_SENT
>> tcp4       0      0 host.52561         147.237.76.155.http    =
SYN_SENT
>=20
> Yes, your side is trying to connect out.
> Unless you know better, it seems reasonable to gather that it's doing =
a DoS attack against:

Hi Chuck!

Thanks.  I am investigating as this side should not be going out at all, =
but the SYN_SENT made me think it was.

Thanks
Chad

>=20
> % whois 147.237.76.155
> [ ... ]
> inetnum:      147.237.0.0 - 147.237.255.255
> netname:      IL-GOVT-NET
> descr:        Israeli Government Network
> country:      IL
> admin-c:      AT979-RIPE
> tech-c:       TT441-RIPE
> status:       ASSIGNED PI
> mnt-by:       GOV-IL-DNS
> mnt-lower:    GOV-IL-DNS
> mnt-routes:   AS8867-MNT { ANY }
> mnt-routes:   AS9116-MNT { 147.237.232.0/24^24-24 }
> source:       RIPE # Filtered
>=20
> person:         Admin Tehila
> address:        Israel Ministry Of Finance
> address:        1 Netanel Lorech st
> address:        Jerusalem  Israel
> phone:          +972 2 6664666
> fax-no:         +972 2 6664650
> remarks:        For ABUSE and security issues please contact
> remarks:        email: abuse@tehila.gov.il
> remarks:        or contact CERT.gov.il at report@CERT.gov.il
> nic-hdl:        AT979-RIPE
> source:         RIPE # Filtered
>=20
> Regards,
> --=20
> -Chuck
>=20




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