Some multicast DNS packets are missing during air sniffing using wireless adapter.

NikithaG
Conversationalist

Some multicast DNS packets are missing during air sniffing using wireless adapter.

Hi Meraki Community,

 

I am trying to capture packets during air sniffing using wireless adapter in the below-mentioned scenario:

 

Device A and Device B are connected to a Wireless router. Device A is sending mDNS packets. These mDNS packets are seen in tcpdump captured at the wireless interface of Device B.

But the same packets are not being captured during air sniffing using wireless adapter.

 

I am making sure that all the steps mentioned in the below link are taken care.

https://community.meraki.com/t5/Wireless-LAN/All-the-packets-are-not-being-captured-during-air-sniff...

 

Kindly do the needful.

 

Thanks & Regards,

G. Nikitha.

4 REPLIES 4
BrechtSchamp
Kind of a big deal

Re: Some multicast DNS packets are missing during air sniffing using wireless adapter.


@NikithaG wrote:

 

But the same packets are not being captured during air sniffing using wireless adapter.


Are you talking about a packet capture on the wireless interface of the MR? Or what wireless adapter are you talking about?

NikithaG
Conversationalist

Re: Some multicast DNS packets are missing during air sniffing using wireless adapter.

The network adapter that i am using to sniff in the air is mentioned below:

https://downloads.linksys.com/downloads/datasheet/1224638657474/WUSB600N_V10_DS_A-WEB.pdf

BrechtSchamp
Kind of a big deal

Re: Some multicast DNS packets are missing during air sniffing using wireless adapter.

I'm afraid I won't be able to help you further on this one. I have no experience with that device. While this is not a Meraki problem but rather a Linksys problem, someone else on here may be able to provide some hints or troubleshooting steps.

NolanHerring
Kind of a big deal

Re: Some multicast DNS packets are missing during air sniffing using wireless adapter.

Your issue might be because that adapter is old and doesn't support 802.11ac from the looks of it. You'll want to have a 3-stream 802.11ac adapter to make sure your able to actually decode all frames, otherwise, you'll just see management frames instead of data.

You'll want something better like this:

https://www.amazon.com/gp/product/B01GE9QS0G/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeAS...

Easiest thing is to use a recent edition of a MacBook Pro laptop to do captures with.

Have a look here to help you get going some, keep in mind this i just the tip of an iceberg:

https://www.cwnp.com/nola-ppt-pdfs/WedPresentations/Jay%20Savvius%20-%20Packet%20Capture%20and%20Ana...

https://www.cisco.com/c/en/us/support/docs/wireless-mobility/80211/200527-Fundamentals-of-802-11-Wir...
Nolan Herring | nolanwifi.com
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