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My CMTS is a Cisco UBR 10K, but I didn't found information about rate
limit.<br>
<br>
Patricio Latini escreveu:
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<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">Daniel,
you should activate dhcp throttling in your CMTS. Advanced
CMTSs support rate limiting features that limit the quantity of DHCP
DISCOVERS/REQUESTSs in order to avoid this kind of DoS attacks<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">Patricio<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span
style="font-size: 10pt; font-family: "Tahoma","sans-serif"; color: windowtext;">From:</span></b><span
style="font-size: 10pt; font-family: "Tahoma","sans-serif"; color: windowtext;">
<a class="moz-txt-link-abbreviated" href="mailto:dhcp-users-bounces+p_latini=hotmail.com@lists.isc.org">dhcp-users-bounces+p_latini=hotmail.com@lists.isc.org</a>
[<a class="moz-txt-link-freetext" href="mailto:dhcp-users-bounces+p_latini=hotmail.com@lists.isc.org">mailto:dhcp-users-bounces+p_latini=hotmail.com@lists.isc.org</a>] <b>On
Behalf Of </b>"Daniel
D. Gonçalves"<br>
<b>Sent:</b> Monday, July 12, 2010 5:39 PM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:dhcp-users@isc.org">dhcp-users@isc.org</a><br>
<b>Subject:</b> DISCOVERY STORM DoS ?<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span class="longtext"><span
style="background: white none repeat scroll 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">I'm
having the following problem, a client begins randomly sending a storm
of
requests DISCOVERY, and DHCP responds with a OFFER, but </span></span><span
class="longtext">nothing more than that<span
style="background: white none repeat scroll 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">.
</span>These
requests cause denial of service on DHCP. <span
style="background: white none repeat scroll 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">Even
removing the MAC from DHCP, the DISCOVERY continuing.</span></span><span
class="shorttext"><span
style="background: white none repeat scroll 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">
I tried these versions </span></span>V3.1.1
and 4.1.1-P1<span class="shorttext"><span
style="background: white none repeat scroll 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">,
both have
the same problem. </span></span><span
style="background: white none repeat scroll 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;"><br>
<span class="shorttext">The IP 10.40.0.1 is a Cisco CMTS with dhcp
relay
activated.</span></span><br>
<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPOFFER on 200.XX.XX.XX to
08:10:74:33:3a:af
(Router) via 10.14.0.1<br>
Jul 12 12:03:03 gw dhcpd: DHCPDISCOVER from 08:10:74:33:3a:af (Router)
via
10.14.0.1<br>
<br>
Thanks.<br>
<br>
Daniel<br>
<br>
<br>
<br>
__________ Information from ESET Smart Security, version of virus
signature
database 5267 (20100710) __________<br>
<br>
The message was checked by ESET Smart Security.<br>
<br>
<a moz-do-not-send="true" href="http://www.eset.com">http://www.eset.com</a><o:p></o:p></p>
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<br>
<br>
__________ Information from ESET Smart Security, version of virus
signature database 5267 (20100710) __________<br>
<br>
The message was checked by ESET Smart Security.<br>
<br>
<a moz-do-not-send="true" href="http://www.eset.com">http://www.eset.com</a><br>
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