I’m sorry for causing confusion.
Technically there’s only 1 ISP, and the contract includes 1 static IPv4.
This static IPv4 is bound to a MAC, and I need to maintain this with the ISP directly.
In theory I can maintain the MAC of router or any other MAC.
I decided to maintain the red NIC of NethServer, connect this NIC with the router and bridge the relevant port internally in the router.
Hereby the router is bypassed by any traffic going through this port and only acts as a modem.
In this picture the host would be represented by NethServer.
And there’s another LAN provided by NethServer green NIC -> 192.168.100.0/24
If you think this makes sense, there’s another question.
NethServer is running on a VM (KVM) with 3 virtual NICs.
Should I maintain the MAC of virtual NIC (red) or the MAC of physical NIC bound to virtual NIC?