MiguelBazil

In essence, the default route is the IP that is selected for traffic forwarding when no next hop, or other rules, matches. Usually you assign it to the router you're connected to, because that's the point on your network that decides where traffic goes. You can either get that info from DHCP if you receive IP configuration from the network, or you'll have to configure it on the card manually. Last resort, it's what I used to do, where Unraid selected the wrong default route interface, and I had to go to Unraid's console, delete the route from 1 interface, and manually create it for the other. If the default route is pointing to the right router IP, using the right network interface, you won't have to delete it. If the IP/interface combo is not right, then yes, you need to recreate it like I did, and probably figure out why the system is not pointing to the right place. It really depends on your scenario. I'd say, write down the current configuration you have, restart unraid, and observe. If you have to reconfigure it after the restart, then it's possible that you will have to continue doing it every restart until something changes. In my case, it was essentially making sure that I had a single network interface available on Unraid. That way, he had to use that one. Once that happened, Unraid automatically selected the right default route. If you can access everything you want, then it should be. 95% of the times, you shouldn't need to care about that, as long as the network allows you to do what you need. The other times are when you want to screw around and find out 😁

I wish, but no. Eventually I got a fiber optics upgrade in my house because I started playing with homelabbing, which led to have a single fiber-optics card with 2 ports, and the issue got solved that way. Port 2 of that card doesn't have an SFP, and as such, never gets configured, which means, single port. I still would like to know those things because I do think it'd help to create some more specific configurations for users, but no dice. If anyone ever finds the info, feel free to tag me.

I thought so too, but that's not the case. It goes even further: if I have an interface assigned to eth0 and another to eth1, and I switch assignments, the default route moves with the assignment. In a sense, it's similar to rmp5s issue. That's why I'd like to understand exactly how it's determining these things. There are a few things I'd like to also be able to do, like configuring an interface to ALWAYS start down, for example. Maybe that could solve both problems. The reality is that I don't know enough of the base OS to even try to do it through a script that at that level. Up until now, I've connected to unraid after each restart, and manually recreate the routes. With the latest version (7.x.x), I can't even do it through the network, as the interface is not responding properly until I set the correct default route... That means I have to physically go to the server, and add it there, otherwise I don't have network connectivity. Not an option if I'm away and there's a power outage.

I've been waiting for an answer to this question for a very long time. I'd like to know how the OS determines which interface to use as the default route. As an example, I have a 10GBE PCI-E card, that has two interfaces: eth0 and eth1. Eth1 is always disconnected, but always gets picked for the default GW for the network. Every time unraid starts, I have to go into it, and manually reconfigure the network. So, is there a way to change this? Even if it's going into the console and changing some files? Because I'm pretty sure that if we could have this knowledge, we'd solve the problems discussed here.

I just wanted to thank you, because I really needed this! It worked perfectly.