Remote Access When Using Multiple NICs - Issue, Resolution and Requested Fix

[cft76011]

Server Version#: 1.29.1.6276

I did a completely new system build for my home server which houses Plex. Part of my upgrade process was the purchase of a Realtek Dual GbE PCIe x1 NIC to complement my motherboard’s single built-in port. My plan was to dedicate an interface to Plex in the hopes that this would help alleviate some bandwidth issues on my LAN in the event I would be doing a large file download while someone is trying to watch something. This, in addition to adding a dedicated nVidia GPU for transcoding, has made a world of difference and made Plex overall such a better experience for my family.

In the process of doing all of this I ran into some trouble getting Plex to send data down the desired ethernet adapter even though I specified which interface to use in the Settings → General → Network section. The problem was particularly troublesome with Remote Access which simply would not work unless I changed my firewall NAT/Port Forwarding rule for Plex back to the main interface’s IP which is .100 and Plex is supposed to use .99. I found through troubleshooting that I could get Plex’s data to flow through the right interface if I altered the Interface metric in the TCP/IP settings in Windows for both the Plex (.99) and general LAN (.100) interfaces to give Plex the lower value and thereby giving it priority. The problem with this solution is now ALL of my traffic was going down the interface that was supposed to be solely for Plex so that was no solution.

Additionally there seemed to be no way to convince Plex that the .99 address was the correct IP / interface to use in the Settings → Remote Access section. As can be seen in the attached picture which was generated today Plex still shows the Private IP as the .100 address despite that not being the Preferred network interface selected under the Network section or what is configured in my firewall rules in my router (also pictured). As a sidenote UPnP in my router is disabled for a multitude of reasons. I only mention this because I seem to recall somewhere reading that UPnP had some part to play in getting Remote Access to function properly. I also read in these forums somewhere that it could take a day or two for that Private IP in Remote Access to update, but this has been a couple of months ago now and I have never seen it shift to the .99 address except briefly after I changed the interface metrics mentioned in the previous paragraph.

So, now to my solution, that I have had work consistently for me these last couple of months and slowed my posting of this here because when something works … well you know, but it has its problems.

So through further Googling and persistence of wanting to accomplish what I set out to do I discovered that if I edited the five Windows firewall rules (pictured as well) that Plex creates for itself during install and forced the Local IP Address under Scope to be 192.168.88.99 then everything works exactly the way I want it to. However, every single time Plex has an update it wipes my custom entries and re-applies the defaults so I have to go back in and re-enter the IP address 5 times each time. I will make a script to make that easier on myself as it is getting a little annoying, but I wanted to post my experience on here in the hopes that Plex might find a way to make this better for those of us trying to implement such a configuration with multiple NICs and wanting to dedicate one solely to Plex. In addition, I hope my posting this information helps others and I welcome any comments or suggestions that would make this configuration work more smoothly.

Update: Here is the simple PowerShell script for updating Plex’s 5 firewall rules with a forced Local IP Address

 Set-NetFirewallRule -DisplayName "Plex DLNA Server" -LocalAddress "xxx.xxx.xxx.xxx"
 Set-NetFirewallRule -DisplayName "Plex Game Transcoder" -LocalAddress "xxx.xxx.xxx.xxx"
 Set-NetFirewallRule -DisplayName "Plex Media Server" -LocalAddress "xxx.xxx.xxx.xxx"
 Set-NetFirewallRule -DisplayName "Plex Scripting Host" -LocalAddress "xxx.xxx.xxx.xxx"
 Set-NetFirewallRule -DisplayName "Plex Tuner Service" -LocalAddress "xxx.xxx.xxx.xxx"

[dduke2104]

A lot to digest here.

You are introducing a lot of issues for Windows in general putting two NICs on the same subnet especially with both local and remote clients involved. I think you’d likely get just a good a benefit by just teaming your two NICs.

It’s going to be pretty hard to overwhelm a single Gbit NIC even with multiple local high-bit-rate plays going on. And of course, remote users are going to likely to hit your Internet bandwidth limit long before your PMS’ Gbit NIC.

My recommendation is that you put together a single Gbit NIC PMS box and do some testing first.

[cft76011]

Well, I’m a guy so I like to compartmentalize things.

I will admit doing the CPU upgrade from a 2nd gen Intel Core i5 to a 5000 series Ryzen and adding a dedicated nVidia GPU for transcoding likely alleviated any perceived bottlenecks I was experiencing. Trying to send all of the traffic down a different NIC may indeed be overkill, but I was trying to do anything I could to alleviate what had been happening on the old setup which was a lot of the “spinning circle of caching” coming up.

Despite knowing this it’s something I would still like to separate to satisfy my own unique brand of OCD and my question then becomes if Plex allows you to pick your preferred interface under the Settings → Network why does it not abide by that choice for the remote access or even for local access? What does that setting do for a user if not to designate which path to use for inbound and outbound traffic? I could open task manager and start watching a movie on another device on my local network and prior to my firewall changes I could plainly see it was always using the interface on the motherboard (.100) which was not what I specified and the same occurred for my phone when I got off my Wi-fi and got on my cellular service. Then after I made the Windows Firewall changes to use a specific local address it began doing exactly what I wanted and it works perfectly. And that’s even with the Remote Access page saying it is working correctly on the wrong local IP.

I promise I’m not in any way trying to be pain in the backside. I am just curious and want to understand what that particular setting does and if this is a poor network configuration then how is it working so well with what turned out to be a pretty minor tweak to the Windows Firewall?

Thanks for responding and I really do appreciate the interaction and information. My goal is to understand all of this better because at the moment my configuration for Plex and its subsequent behavior doesn’t make sense to me with the settings I’m specifying followed by the workaround that fixed the problem.