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Unknown data link type -1

asked 2022-11-23 17:27:44 +0000

nbal gravatar image

Using wireshark 3.2.3 on Ubuntu 20.04.

Reinstalled my PC from backup after a hard disk failure. Had to reinstall wireshark. Now I am getting "unknown data type -1" when I try to capture from my loopback. Running as regular user with on the wireshark group.

What does it mean?

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Did you logout and login again?

Jaap gravatar imageJaap ( 2022-11-23 19:37:31 +0000 )edit

Yes. A few times. It means that I have no permission to capture data on my loopback. I use the group wireshark. Doesn't it work? I have no problems using WS with a sudo...

nbal gravatar imagenbal ( 2022-11-23 20:24:18 +0000 )edit

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answered 2022-11-23 22:26:02 +0000

nbal gravatar image

updated 2022-11-24 04:30:03 +0000

This is due to lack of permission to capture from my loopback. I am using the group wireshark. Have booted several times. I have no problem running WS with sudo. I suspect that the problem is that WS never really created the group "wireshark" during installation. I had to do that myself. How does WS know the gid of a group, that it didn't create? Could this be the reason it doesn't work? What can be done about it? And while on that subject, why don't you change that message from "unknown data type -1" to "Insufficient permissions to access interface"?

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Then, did you usesudo dpkg-reconfigure wireshark-common?

Jaap gravatar imageJaap ( 2022-11-24 05:42:05 +0000 )edit

No I didn't. Too many security warnings, and that sudo:( But i tried it and it works. Thank you so much:)

nbal gravatar imagenbal ( 2022-11-24 06:21:18 +0000 )edit

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Asked: 2022-11-23 17:27:44 +0000

Seen: 32 times

Last updated: Nov 24