pages tagged cdpwiebel.orghttp://wiebel.org//tag/cdp/wiebel.orgikiwiki2014-07-08T09:07:36Zcdp by tcpdumphttp://wiebel.org//linux/network/cdp_by_tcpdump/2014-07-08T09:07:36Z2012-05-15T15:45:16Z
<h1 id="gatherahrefhttps:en.wikipedia.orgwikicisco5fdiscovery5fprotocolciscodiscoveryprotocolainformationswithtcpdump">Gather <a href="https://en.wikipedia.org/wiki/Cisco%5FDiscovery%5FProtocol">Cisco Discovery Protocol</a> informations with tcpdump</h1>
<p>No cdpr at hand, no problem just throw this little <em>tcpdump</em> line at the interface of your interest:</p>
<pre><code>tcpdump -nn -v -s 1500 -c 1 'ether[20:2] == 0x2000' -i eth0
</code></pre>
<p>If there are more than only CDP packets you may narrow it down to the Broadcast MAC:</p>
<pre><code>tcpdump -nn -v -s 1500 -c 1 'ether[20:2] == 0x2000 and ether dst 01:00:0c:cc:cc:cc' -i eth0
</code></pre>
<p>Oh, and don't forget to wait for up to 60 seconds.</p>
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