Bond NICs

If you're running a release prior to Bullseye you'll need to initialise the devices as follows (/etc/network/interfaces):

auto enp6s0
iface enp6s0 inet manual
auto enp7s0
iface enp7s0 inet manual

If the router supports 802.3ad, bond the links:

auto bond0
iface bond0 inet static
  address 192.168.0.2/24
  gateway 192.168.0.1
  # Pre-Bullseye releases use "slaves" in place of "bond-slaves"
  bond-slaves enp6s0 enp7s0
  bond-mode 802.3ad
  bond-miimon 100
  bond-downdelay 200
  bond-updelay 200
  bond-lacp-rate 1
  bond-xmit-hash-policy layer2+3

Alternatively, use bond-mode active-backup:

iface bond0 inet static
  bond-mode active-backup
  bond-miimon 100
  bond-downdelay 200
  bond-updelay 200