I have the usual Unraid NAS setup of a motherboard's built-in 1G Ethernet port and a 10G SFP+ NIC. For a while I used Ethernet to connect to my ISP-provider's internet router/switch while having a point-to-point 10G link to my PC's own SFP+ card.

 

A little ago I got a cheap Chinese switch with a pair of SFP+ ports and four Ethernet ones, one of those connected to the ISP router/switch in turn, so that the NAS and PC can both talk to each other at SFP+ 10G speeds and access internet and my WIFI at 1G ones. The NAS's Ethernet port is now empty.

 

My issue is:
 

• THIS WORKS: If I let Unraid reset to its default networking settings (by deleting the relevant files and rebooting), it bonds the 10G NIC to the unplugged 1G one and everything works, static DNS included. Having the unplugged one be the primary sounds a bit silly, though, and also leads to this question: as the 10G NIC's settings get hidden while in its bonded state: should I de-bond it to change its MTU settings and re-bond? Or should I set them in the eth0's "Desired MTU" field? What happens at the MAC level? Etc.

 

• THIS DOESN'T WORK: if I do what seems tidy, which is set Interface Rules so that the 10G NIC becomes eth0 and the unplugged 1G one is eth1, no bonding, for some reason the 10G NIC can't access manually entered static DNS addresses (such as 1.1.1.1 or 8.8.8.8: pings fail). It can access everything in the LAN and transfer data, though. My PC has no trouble accessing DNS servers, so, I'm assuming it's not a Chinese switch issue.

 

(I've seen suggestions such as disabling the Ethernet port at the BIOS level, but one might want to keep it alive for diagnostics and stuff)

 

Given all this, my question is, then: what is the preferred way to configure such a two NICs scenario? And, if it's the one Unraid defaults to, how should one proceed in order to set the bonded NIC card's specific settings?

In short: is this normal?😅😓

Edited March 5, 20251 yr by MetricTonto

You shouldn't bound them and set the MTU as default 1500.

 

5 hours ago, MetricTonto said:

(such as 1.1.1.1 or 8.8.8.8: pings fail).

Then this not only DNS unavailable, it means internet unavailable.

 

I think problem could be 3 possible.

 

1. Some Network switch have a VLAN switch, pls ensure it is disable.

2 When you bond both NIC, then it will use single MAC address to access network. So problem pointing to MAC address binding issue with ISP, you may waiting for 1hrs and try again. ( But according your description, your ISP provide a router for you, so this less likely because this )

3. If the new switch have management feature, then it may have IP conflict with your ISP router.

Edited March 6, 20251 yr by Vr2Io

5 hours ago, Vr2Io said:

Then this not only DNS unavailable, it means internet unavailable.

You are right: I somehow got DNS tunnel vision and missed the bigger picture. As for your other suggestions:

1. I had disabled the switch's VLAN already, to no avail.
2. I have distinct static IPs for each device, and also I have their MACs bound to those IPs in the router's DHCP so that they stay stable when testing them with Unraid's default dynamic IP settings. The router sees all of them correctly.

• 192.168.1.1      ISP's router.
• 192.168.1.2     switch.
• 192.168.1.20   Windows PC
• 192.168.1.254 NAS
• (When both the NAS' 1G and 10G NICs were active, the one acting as eth1 would use 253)

My guess is everything is right with the inexpensive Chinese managed switch, as the PC has had no trouble at all, and the NAS, when bonded, reaches the internet without issues. The thing to note is that, both when the 10G NIC is bonded and un-bonded, the switch and the router see the same MAC and static IP address. So, I don't know what could be going on. I'm trying to find documentation about the network settings' behavior as a whole, but my Google-fu is lacking.

 

I'll keep on trying things and reporting the results. If not getting anywhere, I'll post screenies and config files.

 

Thank you for your assistance 🙂.

So, it seems it's actually normal 🤔:

(Also, I'm realizing now that I didn't set the disconnected motherboard NIC to a different subnet before trying to make the Mellanox the primary one 😒. I'm not sure that would have solved the internet connection, but it certainly ought to have helped)

 

So, case closed, I think. Thank you all 🙂.

Edited March 12, 20251 yr by MetricTonto
Grammar