[SOLVED] Why cant the NIC make its mind up...

drjaymz@

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Jan 19, 2022
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Jul 14 10:46:19 pve1 kernel: eth0: entered promiscuous mode
Jul 14 10:46:21 pve1 kernel: eth0: left promiscuous mode
Jul 14 10:48:22 pve1 kernel: eth0: entered promiscuous mode
Jul 14 10:48:24 pve1 kernel: eth0: left promiscuous mode
Jul 14 10:50:26 pve1 kernel: eth0: entered promiscuous mode
Jul 14 10:50:27 pve1 kernel: eth0: left promiscuous mode
Jul 14 10:52:29 pve1 kernel: eth0: entered promiscuous mode
Jul 14 10:52:31 pve1 kernel: eth0: left promiscuous mode
Jul 14 10:54:32 pve1 kernel: eth0: entered promiscuous mode
Jul 14 10:54:34 pve1 kernel: eth0: left promiscuous mode
Jul 14 10:56:35 pve1 kernel: eth0: entered promiscuous mode
Jul 14 10:56:37 pve1 kernel: eth0: left promiscuous mode

I searched for this but can't work out why I see this all the time. I see it on multiple PVE installations, and I'm not really sure what its telling me other than the networking config is updating for some reason.

The device is running home assistant which may be doing some discoverability things that might be related?
 
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It seems to be on a 2 minute timer, so yes, it may be one of your guests (VM or container) doing something funky.

Promiscuous mode means that your NIC is set in a mode where it receives and passes through all frames to the kernel/application, even ones not intended for this host. So this is intended to passively listen for some kind of traffic on the network.
 
It seems to be on a 2 minute timer, so yes, it may be one of your guests (VM or container) doing something funky.

Promiscuous mode means that your NIC is set in a mode where it receives and passes through all frames to the kernel/application, even ones not intended for this host. So this is intended to passively listen for some kind of traffic on the network.
can a guest VM do that? In Hyper-V you can but not without configuration.
 
I just remembered I have watchmylan community script container running in there as well, I will turn that off for 20 mins and see if that clears it.
 
Remember that LXC logs are also seen from the host itself. Your container is setting it's own nic (eth0) in promiscuous mode (i.e. will be able to see all traffic in that L2 segment), not the host's nic.
 
Running only Home Assistant VM, I also have similar logs on the host node from time to time, though only for interfaces (tap etc.) used by the VM. I cannot correlate the timings of these logs with Home Assistant VM activity. I imagine it is linked with certain integrations/addons being used. I've never knowingly experienced any pitfalls because of these logs.
 
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Remember that LXC logs are also seen from the host itself. Your container is setting it's own nic (eth0) in promiscuous mode (i.e. will be able to see all traffic in that L2 segment), not the host's nic.
This is what it is. Its reporting eth0. Its part if how that container does its work.