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I'm trying to capture cdp and lldp packets from my cisco 2960 switch. This works just fine on a desktop computer but if i try to do the same thing on my laptop wireshark never gets the cdp packets at all.

and i know it is being transmitted by the switch since my desktop works fine in the same network port and is able to display the cdp packets.

The laptop is a hp 6930p with an intel network card, desktop is also an intel network card.

Is it possibel that the network card or drivers somehow filter out the cdp multicast traffic and never forward it? any advice on how to fix this?

asked 21 Oct '11, 06:55

tobbe's gravatar image

accept rate: 0%

I see no reason why the laptop should not show the CDP packets. Have you got VPN software installed? They are notorious for messing up capturing. Are you able to see other multcast traffic (HSRP for instance)?

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answered 21 Oct '11, 07:12

SYN-bit's gravatar image

SYN-bit ♦♦
accept rate: 20%

thanks, i found the problem. mcafee host intrusion prevention software is interfering with the cdp packets. removing it makes the cdp packets show up correctly.

only vpn i have is the built in ms pptp.

(21 Oct '11, 07:25) tobbe
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question asked: 21 Oct '11, 06:55

question was seen: 4,757 times

last updated: 21 Oct '11, 07:41

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