I am trying to setup a NUC computer (using ubuntu 18.04) such that:
- ethernet port is connected to a port of a switch set in mirroring mode: The mirroring port only sends mirrored packets, and can't not be used to send from the computer to the network.
- wifi interface is used for access to the network and internet.
When I set the port in mirroring mode, the computer looses access to the internet as it prioritize the ethernet interface and can't reach the network from that mirrored port.
I tried to use the metrics in the /etc/network/interfaces file to deprioritize the ethernet interface as below:
# interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback auto eno1 iface eno1 inet static address 192.168.1.30 netmask 255.255.255.0 gateway 192.168.1.1 dns-nameservers 192.168.1.1 metric 700
The wifi interface is managed by NetworkManager. My resulting route is:
user@host: route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 600 0 0 wlp58s0 0.0.0.0 192.168.1.1 0.0.0.0 UG 700 0 0 eno1 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eno1 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eno1 192.168.1.0 0.0.0.0 255.255.255.0 U 600 0 0 wlp58s0
But when I set the port in mirroring mode, the computer looses connectivity, which I assume is because the destination 192.168.1.0 still has the eno1 interface with highest metric of 0? And I am not sure how to change that.
What I am doing wrong? Is it possible to achieve what I am trying to do? Is the metrics approach the wrong way?
Thanks for any pointers