My goal is to create a redundant internet connection. I have a USB-LTE Modem and a wired connection. I work on ubuntu 16.04. I can use both on their own but I want to combine them together to create redundancy. Now I searched for solutions and found the kernel bonding module.
I tried multiple configurations. The mode I want to get working is the active backup mode as this is the mode which would give me redundancy.
What I achieved: I can add both interfaces to bond0 and ping though that interface (tested with ping and route). The output from
/proc/net/bonding/bond0 also looks fine for me:
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011) Bonding Mode: fault-tolerance (active-backup) Primary Slave: usb0 (primary_reselect always) Currently Active Slave: usb0 MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 200 Down Delay (ms): 200 Slave Interface: usb0 MII Status: up Speed: Unknown Duplex: Unknown Link Failure Count: 0 Permanent HW addr: 02:1e:10:1f:00:00 Slave queue ID: 0 Slave Interface: enx00044b580af6 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 0 Permanent HW addr: 00:04:4b:58:0a:f6 Slave queue ID: 0
However, if I test the worst case and remove the USB-LTE Modem the connection is lost completely (can't even ping anymore). So no redundancy at all.
My guess is that I have a dhcp/gateway problem here. Because the both slaves interfaces have a complete different ISP etc. Sadly, I don't have a lot of experience with networking on linux and can't solve it on my own.
So my Question: Is it possible to bond two such different connections together with the bonding module? And if yes, any ideas how?