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I have a question that is pretty similar to this post here: https://ask.wireshark.org/questions/26732/incoming-udp-only-works-while-capturing-packages-with-wireshark

I tried everything listed there but I'm still stuck. Im using a separate program to listen to any ip/port number I specify. I can only see my data in that program when wireshark is running.

My dest mac address is pointing to my nic card. My source mac is my boards mac. My ip addresses I picked randomly. On my receiving computer I am listening to my destination ip and udp port I specified in the packet. My checksum is correct, but I had to go into the wireshark settings and enable verification. I'm not sure if that should have happened by default.

I constructed the entire packet myself on the send end so I can change any values I want. Here is my capture. I can add more data if that would be useful but all the packets have the exact same headers. my capture 1 packet

Could this have something to do with windows throwing away the packet unless wireshark (in promiscuous mode) keeps the packet. Then my program can see the data?

Thank you!

asked 23 Jan '17, 10:27

mfpentek's gravatar image

mfpentek
11114
accept rate: 0%


Normally, that kind of behavior is caused by the receiving NIC being in Promiscuous Mode during a capture, accepting all MAC addresses - so you should take a very close look and check if the destination MAC really matches the NIC MAC.

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answered 23 Jan '17, 10:35

Jasper's gravatar image

Jasper ♦♦
23.8k551284
accept rate: 18%

1

Yup, looking over the mac again, its off by one bit. 2nd answer where you saved my behind, you really know your stuff. Thank you so much!

(23 Jan '17, 12:05) mfpentek

You're welcome!

(23 Jan '17, 12:27) Jasper ♦♦
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question asked: 23 Jan '17, 10:27

question was seen: 917 times

last updated: 23 Jan '17, 12:27

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