It can be helpful to bond physical network interfaces together on physicals hosts so that software can treat multiple network connections as a single interface to while spreading the load across all members. Linux, and Debian derivatives in particular benefit from a kernel module called ifenslave. It's referenced here: https://wiki.debian.org/Bonding.
I've used this for clustering storage systems, as well as VM/Container hosts to ensure consistent and fast network access. Here is some working examples below.
# # This is an example of /etc/network/interfaces # Reference this manpage for configuration options: https://www.kernel.org/doc/Documentation/networking/bonding.txt # # It is important that the interfaces listed first are # initialized first to last as described in the configuration file. # For Example to Create a logical interface(a) on top of another logical interface(b) # the logical interface(b) would need to already exist. # # Bonds Primary/Backup auto bond0 iface bond0 inet manual up ifconfig bond0 up slaves eth1 eth3 eth5 bond_mode 802.3ad bond_miimon 150 bond_downdelay 200 bond_updelay 200 auto bond1 iface bond1 inet manual up ifconfig bond1 up slaves eth0 eth2 eth4 bond_mode 802.3ad bond_miimon 150 bond_downdelay 200 bond_updelay 200 # Bonded HA auto bondha iface bondha inet manual up ifconfig bondha up slaves bond0 bond1 bond_mode active-backup bond_miimon 310 bond_downdelay 200 bond_updelay 200 # IPs in VLANs auto bondha.1 iface bondha.1 inet static up ifconfig bondha.1 up address 10.0.1.1 netmask 255.255.255.0 vlan-raw-device bondha gateway 10.0.1.254 dns-search pdx.atwlab.com dns-nameservers 184.108.40.206, 220.127.116.11, 10.0.1.254 auto bondha.100 iface bondha.100 inet static up ifconfig bondha.100 up address 10.0.100.1 netmask 255.255.255.0 vlan-raw-device bondha gateway 10.0.100.254 dns-search pdx.atwlab.com dns-nameservers 18.104.22.168, 22.214.171.124, 10.0.100.254