>
> grandstream.yagibdah.de (192.168.3.80) auf 00:0b:82:16:ed:9e [ether] auf
> enp2s0
> grandstream.yagibdah.de (192.168.3.80) auf 00:0b:82:16:ed:9e [ether] auf
> enp1s0
> spa.yagibdah.de (192.168.3.81) auf 88:75:56:07:44:c8 [ether] auf enp2s0
> spa.yagibdah.de (192.168.3.81) auf 88:75:56:07:44:c8 [ether] auf enp1s0
>
>
> enp2s0 is an interface dedicated to a PPPoE connection, and enp1s0
> connects to the LAN.
>
> IIUC, this is bound to cause problems.
>
> How is it possible for the wrong entries to be created, and what can I
> do to prevent them?
>
>
arp mappings are untrusted so your machine will accept anything is sees on
the network. That's what makes MITM so easy on a connected subnet. What
makes you think they are wrong? Also, the output of ifconfig would be
helpful.
