Empty share when using more than one IP/interface on the server

Artbananza

Cadet
Joined
Dec 21, 2022
Messages
5
My apologies in advance if something here might look silly. Please bear with me.

I have a TrueNAS Core (13.6) server that handles many SMB shares for hundreds of clients (Win10) over WAN and over LAN. Most of the clients on the WAN are just moving back and forth small documents and some occasional scans. However, on the LAN, clients deal with rather heavy graphic files, large archives, and, in general, many people work directly from the network share. So, in pursuit of better performance and to avoid upgrading network hardware, I decided to connect these users with an additional link from an empty 10G port on my server to the switch that operates in the subnet of those users.

From a networking point of view, the setup looks like this:

Main link = 172.16.0.55/24 (SFP+ port #1 in the server's NIC)
Secondary/additional link to the switch of "special" users = 172.16.200.55/24 (SFP+ port #2 in the server's NIC).
Special users live in 172.16.200.100-150/24

Everything worked just fine until we had to replace our AD server and create a completely new one with all new users and settings. After I "left" the old AD domain on the TrueNAS, connected to a new one, and changed ACLs on files, I encountered an unexpected problem.

When I'm connecting to the server using the secondary IP 172.16.200.55, I don't see any shares whatsoever. This is weird for two reasons: firstly, on my "main" connection, everything is working as expected—I can see and interact with all the shares in accordance with the access rules I've set up. Secondly, after switching AD domains, the secondary connection was behaving just fine for a few hours at night. But in the morning, all of a sudden, you are unable to see any shares using 172.16.200.55, regardless of under which username you are logging in.

Naturally, my first order of business was to double-check everything, reboot, restart, create some new shares (with pristine ACLs), etc. Well, that hasn't got me any closer to solving the problem. Google wasn't much of a help either. I saw a couple of posts where people discussed that Samba can behave weirdly and "hide" shares in rare cases when it shouldn't, but the proposed solution of recreating shares and setting up correct ACL rules didn't help me.

Right now, I have connected everyone using the main link, but this is only a temporary band-aid because all the traffic is now going through the router, which is not suited for that kind of load (and it creates some congestion).

If anyone has any suggestions on where/how to begin to tackle this problem of missing shares, please share it (pun unintended).
 
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Artbananza

Cadet
Joined
Dec 21, 2022
Messages
5
Well, the story ended the same way most of these stories end—with human error being discovered. It turns out one of our team members was running around, juggling dozens of issues in his head while extinguishing fires, figuratively speaking. As a result, on one machine, instead of connecting the share as a mapped drive using 172.16.200.55, he assigned this IP as a static IPv4 address for that particular machine.

This explains the fact that we were able to connect to this IP but didn't see any shares. The machine accepted the connection because we were using one of AD's admin credentials to connect, and, of course, after connecting, we did not see any shares because this PC didn't have any.
 
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