Two Players Connecting from Same Network Disconnects Each Other from Host

[gryansmith]

Greetings All,

I hope I am posting this in the correct place. If not, please feel free to move the thread. Additionally, I'm sure there are other threads that would be helpful that I was unable to find in my searching. Please feel free to just link me somewhere and I'll do the necessary reading...

My partner and I have been using FGU for a while with some friends who have played for many years. All of them are on individual networks. We are the only ones who connect on the same personal home network. I am generally hard wired to our router/modem and she is usually on WiFi. We run into an issue in which often when one of us is connected and in session, then the other connects, the first person is kicked out of the session. This happens back and forth, regardless of which of us joins first, and we have to restart repeatedly until it, for whatever reason, decides to work.

We just switched GMs after ending a campaign and I thought maybe another host/GM would make a difference, but it has not. It's almost worse, seemingly, the one session we played.

I've attached a .zip of logs from the last incident this past weekend. Does anyone have any thoughts or recommendations?

Thank you,
Ryan

[Trenloe]

Welcome to the FG forums. Sorry you're having issues.

Do you and your partner both have free FG licenses?
What license does the GM you're connecting to have?

[Moon Wizard]

I'd need to see logs from the GM as well as the players when the incident occurs to get any idea from the logs what might be happening.

However, in almost every situation where we have had people report networking issues, the issue has tied back to firewall/router settings. Please take a look at the Network Troubleshooting wiki article to see what kinds of items you can look at.
https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/1981349889/Network+Troubleshooting

Given that the issue stems from both players trying to connect on same network and individually they appear to connect just fine, I would focus your investigation on your Internet router settings. I would specifically look for anything in the settings specific to additional firewalls or throttling. (i.e. SPI filter, parental controls, QoS (quality of service), etc.)

Regards,
JPG

[gryansmith]

Trenloe, JPG,

Thank you both very much for the quick responses. It’s very much appreciated. Our GM has an Ultimate license. My partner and I are both using free licenses. Would standard make a difference?

I don’t have logs from the GM during the incident, but I will ask them to if the issue persists so I may post them here.

Network / router settings makes sense as the likely issue. Thank you for providing that link. I will give it a review and tinker to see what I can find and adjust.

[LordEntrails]

If the GM has Ultimate license then that's not the issue. Trenloe was (I assume) wanting to eliminate the issue that if the DM has a Standard license, then only 1 Free user can connect, the second one to do so will be disconnected.

[gryansmith]

Understood - thank you for clarifying. No, GM has ultimate and we have two other players who join regularly as well who do not seem to have this disconnect issue. So likely then it seems it's our network, which I will dig into. I appreciate the help and support. We love the platform, just not our own connectivity issues!

[TVDinner]

Here's a wild *** guess.

This is kind of technical, if you don't understand, say so and I'll try again.

Does the hardwired machine have a fixed IP address (configured in windows) and the wifi machine have an IP address assigned by the "router" (via DHCP)? If so, the IP address for the hardwired machine needs to be outside the range of IP addresses that the router allows for DHCP.

The error of note that shows up in all three logs is "The requested address is not valid in its context." I think this means that the network connection, from a windows perspective, is disappearing and reappearing after FGU starts up.

[TVDinner]

I've left a server running for you to have both clients connect. If you see the failure, stop trying to connect. That'll get the server logs quicker.

GM TVDinner
campaign RyanTest
password Wifi

[BronzeDodger]

Possible cheap test: if you have a VPN client like ExpressVPN or Nord VPN (and they both look to have free one month trials if not) try using the VPN client on one, leave the other alone. If FGU is mistakenly booting the second connection because as far as the DM's PC can tell, it's two connections from the same real-world IP address, using a VPN client would probably defeat that, as the DM's machine would see two different IPs arriving.

[TVDinner]

I saw some connections and grabbed the logs as of noon central. Partner is still disconnecting and reconnecting, I'll probably grab the logs again in a bit. The big question is "did the failure happen and if so, when?"

[gryansmith]

TVDinner - good thinking on the automatic versus configured IP address. Both devices were on automatic. Presumably they were not duplicating if both handling as automatic? See below. I really appreciate you opening a test session. I got on first with the wired machine, then the wireless. At first it was fine, I played around and no issues. I exited the session on the wireless machine and logged back in, and it disconnected the wired computer. Logs attached. That timing was between 12:40p and 12:50p ET.

I then tried your suggestion, BronzeDodger. I downloaded Nord VPN on the wifi/wireless mac machine with neither device in the test session. I then repeated the exercise - signed in first from wired, then wireless. I hopped in and out of the session returning to the launcher a few times with each machine and at no point did either disconnect the other. SO that seemingly appears to be a fix. We will of course try it this weekend in the standard Saturday game. If that does seem to resolve it, is there a way to replicate what the VPN is doing, without a VPN, through our network settings - either machine level, router level, or both? To avoid paying for the VPN? Or do we just accept that VPNs are nice independent of FGU gaming and roll with it? :D

Wired Windows Machine
Link speed (Receive/Transmit): 1000/1000 (Mbps)
IPv6 address: 2601:140:8d00:ce:a951:dba3:318:cbe9
Link-local IPv6 address: fe80::a951:dba3:318:cbe9%4
IPv6 DNS servers: 2001:558:feed::1
2001:558:feed::2
2001:558:feed::1
2001:558:feed::2
IPv4 address: 192.168.0.38
IPv4 DNS servers: 75.75.75.75
75.75.76.76
Manufacturer: Realtek
Description: Lenovo USB Ethernet
Driver version: 10.51.318.2022
Physical address (MAC): 48-2A-E3-6B-B7-3F

Wireless/Wifi M
53086

[TVDinner]

Two logs. One was taken at noon central, the other taken after I saw more connections at 12:22pm.

[TVDinner]

Oh, I should mention for Smiteworks that the two extra network connections that show up in the logs on my machine are from Edge's Application Guard. The class A network is the right one.

[TVDinner]

Both devices were on automatic. Presumably they were not duplicating if both handling as automatic?Yeah, as long as they're both using the same DHCP server. :)

[gryansmith]

Thank you. To confirm, based on the logs you uploaded in central time, this is when the disconnect happened, in case it helps anyone reviewing.

[6/9/2022 11:41:19 AM] 'gryansmith' connected
[6/9/2022 11:41:32 AM] Client connected. Waiting for authorization. [2]
[6/9/2022 11:41:32 AM] Authorization failed: Incorrect password.
[6/9/2022 11:41:47 AM] NETWORK RECV FILE REQUEST: images/decals/
[6/9/2022 11:41:47 AM] NETWORK FILE CACHE MATCH: images/decals/
[6/9/2022 11:42:02 AM] Client connected. Waiting for authorization. [3]
[6/9/2022 11:42:02 AM] 'SaraBautista' connected
[6/9/2022 11:42:24 AM] Campaign saved. (0s)
[6/9/2022 11:42:30 AM] NETWORK RECV FILE REQUEST: images/decals/
[6/9/2022 11:42:30 AM] NETWORK FILE CACHE MATCH: images/decals/
[6/9/2022 11:45:29 AM] 'SaraBautista' disconnected

Disconnect occurred here - I exited the session as Sara after getting both machines on successfully, then tried to login again as Sara, which is what generated the 11:46:59 disconnect as Ryan

[6/9/2022 11:46:59 AM] 'gryansmith' disconnected
[6/9/2022 11:47:12 AM] Client connected. Waiting for authorization. [2]
[6/9/2022 11:47:12 AM] 'SaraBautista' connected
[6/9/2022 11:47:24 AM] Campaign saved. (0s)
[6/9/2022 11:47:39 AM] NETWORK RECV FILE REQUEST: images/decals/swk_decal.png@SmiteWorks Assets
[6/9/2022 11:47:40 AM] NETWORK FILE CACHE MATCH: images/decals/swk_decal.png@SmiteWorks Assets (75152)
[6/9/2022 11:48:53 AM] 'SaraBautista' disconnected

[Moon Wizard]

Unfortunately, there is no information in the logs that provides any light on the situation. This is most likely because whatever is happening with the connections is happening outside the application (i.e. some OS or router feature is closing/blocking the connection), so there is no way for the application to have any information on what is causing the dropped connection.

The fact that the NordVPN session worked just fine lends additional support to some sort of security setting on the ISP router (and any other routers in your network configuration) are causing the connection drops.

Regards,
JPG

[BronzeDodger]

Moon would a session typically be a-ok with two different sessions connecting to the GM from the same IP address? Based on, y'know, zero real facts (but why let that stop me...) if the VPN resolves the disconnects that would suggest something is not liking two sessions arriving from the same source IP. I've tried the "second session on a single PC" trick as the GM, but that calls the localhost so avoids looking like twin of itself (I think?).

@gryansmith trying to not dive too far down the technospeak rabbit hole - while you can have almost unlimited IPs inside your router/firewall, typically every computer shows up externally from the single "real" IP attached to the router on the ISP side. You can see this yourself by searching "what is my IP" on each computer - if both are on the WiFi they'll show up with the same address as far as the world is concerned. One way to test this without the VPN would be :

On a mobile device that permits tethering, disconnect from your home WiFi (might have to delete the profile that the phone doesn't keep reconnecting); basically you need the phone to be using internet from your mobile plan, not via your home WiFi
Activate the WiFi hotspot on the mobile (bluetooth hotspot would work too I suppose, if the PC can use bluetooth)
Connect one of the computers to the hotspot, so that it is getting the data feed from the cellular connection, not from your home internet connection (and make sure it's not also still connected to the home WiFi if you're using bluetooth)

If that works...
Upside: if you have unlimited data on your mobile plan, free way to get a different IP address.
Downside: Ask the GM to share literally anything and see how it goes - a big ugly map will probably be a quick way to discern/compare how long it takes to popup on each of the computers (and what impact it has on performance while it downloads). Entirely possible you'll sprint for a VPN client as the throughput may be pretty poor compared to your internet line in the house - but if you have a 4G/5G device you never know, it might do fine.

[Moon Wizard]

It should not matter that the connection is coming from the same IP address for their home network; we have many users that have that scenario. In the few cases where we've had reports of issues in this particular scenario, it's always been a router setting that is causing issues.

IP address information is encapsulated in network traffic when transferring over network boundaries. The FG application host does not use IP addresses in the connection management directly; just lets the underlying network libraries handle the connections.

Regards,
JPG

(edit: made correction, added forgotten not - LordEntrails)

[TVDinner]

Ryan, what's the make and model of your router?

Others, my IPv6 is weak. I see both v6 and v4 addresses in the client logs and have no idea which version is actually being used by the client to talk to the connection broker. This pings my interest because my server is behind a firewall which will not pass v6, nor does it make a tunnel (I hope). My logs are all v4 (the "noble connect" messages). Something's going to have to connect the client v6 (if true) with my server's v4.

Ryan, I suppose you could try turning off ipv6 in your router (along with the other various settings mentioned earlier). I have a game tonight (Friday) but can leave a server up over the weekend if you've got time.

I used to routinely run three clients and the server on my network and use the connection broker ("public" game). Never had a problem, although it was a bit silly in retrospect. A relic from FGU early testing. :)

[gryansmith]

Moon, Bronze, TV,

I do appreciate your continued engagement on this matter and your support. It’s much appreciated. Candidly, I have not had time to fiddle with router settings. That’s happening tonight/tomorrow. And we have our regular game tomorrow so I will give it a try beforehand. But also want to see how the VPN handles tomorrow.

Bronze, per your suggestion, we have done the hotspot approach in the past. Which does work. But while we have “unlimited” data, it does become throttled at a certain point. So depending on monthly data usage, it isn’t a super sustainable approach.

Make and model is: Netgear AC 1750; C6300v2

Aside from two gaming sessions tomorrow, we can make some time to test things out. Thank you again for the willingness to run a test session!

[damned]

I regularly have had 2 players from same home connected.

[TVDinner]

I've put the server back up as it was and it can stay up. Connect at will.

The router's manual shows it's a pretty basic router with not much to play with. I'd try turning off parental controls, "block service," "schedule when to block," and do not set up a DMZ. The router has some logs, I'd check them but I doubt they'll have anything interesting. Unless you know what they are, make sure port forwarding and port triggering are turned off. I don't see any quality of service, traffic shaping, or other ways to muck with which machine gets priority.

There's no way to turn off ipv6 on the router. You can turn it off on both clients, but don't bother until the other options have been tried. It's not hard to do, it's in the network properties. If there's a network icon on your desktop, right click that, or you can also get to it from the control panel. If you aren't thinking "yeah, I know how to do that," I can also run the server on a machine which is ipv6 connected (I think, I've never actually tried to verify through the ISP). I'll stick my nose in here or you can leave something in the FG chat box. It's not much effort on my part.

This ipv6 theory assumes that your GM also has a ipv4 only connection. You can ask.

-------------
Would someone else with two ipv6 machines on the same network try to connect a few times? That's be the easiest way to stick a fork in that one.
-------------(attention grabbers)

[TVDinner]

I was able to get two v6 clients to connect and reconnect to that server with no problems. I'll leave 'em for a while and try again later, but that theory looks even less likely.

[TVDinner]

So how'd it go?

If you can borrow another router (not another cable modem), you can "disable router mode" on your cable modem. Plug the borrowed router's WAN port into the cable modem and connect your machines to the new router. If external internet doesn't work you'd have to figure out how the borrowed router's WAN port gets it's internet address configured.

[gryansmith]

Thank you for checking back in. It went poorly on Saturday during our session. Started out okay - me wired into our network, my partner wireless on our network with VPN - but then we both started to be disconnected. She switched over to phone hotspot, while I stayed on our network. Even just me was problematic. Would be connected for 10m-15m then disconnected. I fiddled with settings throughout our session, but nothing seemed to be super successful.

There are no parental controls on our device, blocking and scheduled blocking are disabled, and there is no DMZ. Port forwarding was off but port triggering was on. I turned it off, but that didn't resolve things. I tried turning off IPv6 on my network properties and that seemed to help, but disconnects still occurred. I logged into the test session on Sunday with both machines and had no disconnects occur for at least three hours. Is it possible that it's the relationship between our network and our GM's? Is it possible that general increased use and traffic on FGU (weekends versus weekdays) would make a difference? Or increased traffic on our ISP (we live in a condo building so many folks seemingly tapping ISP resources more on the weekend when at home)?

I will see about finding another router to play with.

[Moon Wizard]

Some thoughts for investigation:
* You can also look at any QoS settings on the router, as well as making sure there is no SPI filter or ad blocker type of settings enabled.
* For the GM network, have they checked similar settings on their side?
* For the GM network, are they using Comcast/Cox as their Internet Service Provider? If so, maybe they can check where the "Advanced Security" option is turned on, and interfering.

Related thoughts:
* IPv4 vs. IPv6 shouldn't matter if everything is working, and ISPs aren't doing anything unusual.
* In general, the traffic volume shouldn't matter with most ISPs unless the condo building is providing the Internet service through a shared router, and their router is performing it's own throttling.
* Again, in general, the relationship between your network and GM network really boils down to all the hardware and software layers between your machine and their machine (ISP, router(s), OS network/security, application). That's why a lot of the advice is trying to narrow down which piece seems to be causing issues for you.

Regards,
JPG

[gryansmith]

Thank you, JPG. I do really appreciate the follow up. On our router settings I see, under WAN Setup, "Disable Port Scan and DoS protection". Would it make sense to click that on? Otherwise I'm not finding anything related to DoS. I saw options about security settings in the general network recommendations post - should I try switching from WPA2-PSK to WPA or none? I'll chat with the GM today about their settings and what they may be able to investigate.

[Moon Wizard]

I don't think that DoS Protection would have an impact; but it depends on the specifics of what the router is trying to do. In my previous messages, I was specifically referring to QoS (quality of service) which usually performs throttling on a per connection basis.

Another thought I just had is that if you are using a WiFi access point separate from your router, you may need to make sure that your WiFi access point is in bridge mode and not acting like another router (which would have it's own settings) (i.e. network within a network).

The encryption level of the WiFi (WPA2/WPA2-PSK/etc) should have nothing to do with this; since it's a point-to-point encryption and I'm running similar settings here.

Regards,
JPG

[LordEntrails]

Reading Moon's comment about bridge mode, made me remember that my router has a "AP Isolation mode" that prevents devices from connecting to each other. Maybe your's has similar?

[TVDinner]

Ryan, if you manage to snag another router to try disabling the modem's router or try something else, let me know and I'll put the server back up. The router being the culprit isn't that strange, I had a netgear WGR614 that would drop connections every 50 minutes if my wife was streaming netflix while I was blowing up monsters.

Is there any chance your condo is one of those that resells cable, ie you pay the condo association and not the utility directly? Those setups are notoriously oversold.

It's also unlikely but possible that someone upstream is limiting the total number of TCP connections. Do you have a lot of browser tabs and other stuff running on both clients while FGUing? Is there something else in the house using the network?

When the disconnect happens does it happen suddenly once the other machine connects, or is there some sort of waiting period with a hang and then the disconnect?

Has it ever failed with the VPN trick?