Unable to connect, also distrupts other network applications

84 votes

I'm facing an issue where trying to play Valheim online doesn't only result in disconnects from server before passsword prompt but it disrupts all other network activity on my PC as well - for instance websites load erratically and steam message delivery becomes unreliable. So far I've just rebooted as a fix. On occasion I can join a server (I use Steam overlay), but I can't play for longer than a minute or two. It seems to be hammering my DNS really hard, generating some 5000 reverse DNS queries in a matter of minutes.

Using WiFi with a Windows desktop PC. My network has a DNS level ad blocker and player.log does report that queries to google-analytics failed (it's blacklisted).

Under consideration Suggested by: looz (09 Feb, '21) • Upvoted: 10 Apr • Comments: 30

Comments: 30

09 Feb, '21
looz
Well, the reverse DNS queries are nonsense and probably caused by my troubleshooting software... But it does seem query info of all public servers on launch by default.
09 Feb, '21
Ji
I can connect myself but it does make other connections really weird and wonky for me as well.
10 Feb, '21
Gopher
I have the same problem. Tried flushing DNS, manually setting a DNS address, updating Network drivers. Every time within 30 seconds of joining the server my internet modem completely crashes, wifi, ethernet, etc all down. My internet even died just sitting at the main menu for less than a minute.
10 Feb, '21
MrJoshua
Try lowering this setting, if it's too high your router may get overwhelmed and kill all your connections:

Open the Steam client and use the dropdown menu in the top left of your screen (labeled "Steam") to select Settings (sometimes called Preferences). Click the "In Game" tab, and you will see an option to adjust your max pings per minute. Set this to 1,500 or lower.
10 Feb, '21
Dream WEaver
Are you using the Killer Networking software? If so, uninstall that software.
11 Feb, '21
Gopher
I tried setting up my phone as a hotspot for my PC as a test and was able to join my friend's server without any problems! This seems to narrow down the issue to either an ethernet controller issue or a router/modem issue.
13 Feb, '21
looz
I think I finally understood what is going on. Query for info is much smaller than the response with server name, player count and game version. My connection has a faster uplink than downlink, so I effectively end up DDoSing myself.
16 Feb, '21
ADAM JOHNSON
I am having a similar issue. Is there a fix for self ddos'ing??
17 Feb, '21
Bart
I have the same problem, it seems to take my entire network offline. If the game is open, I can't do anything on the network from any computer. I was able to join a game a few days ago and played for a couple hours with a friend, but now even going to the title screen crashes the network.
18 Feb, '21
Tim
I think I found the fix and it was answered above!

Same issue with me. Wifi would crash trying to load a server but I can play solo.

Steam, settings, in-game, ingame server browser ping limit. I believe it was set automatic 5000. I tried 1500, 1000, all the way to 250 and I loaded in.

Don't know what any of that actually means but it got it to work.
22 Feb, '21
Geoff
I also have this issue. Whenever I attempt to connect to any server, my entire network goes down. Not just the ethernet connection on my computer, every device on my wifi loses internet connectivity. I have to reset my router every time I try to play online.

Edit: Turning down the "Server Browser Pings / Minute" setting seems to have solved the issue.
01 Mar, '21
Maxime
Sadly turning down the Pings / Minute isn't changing anything, does someone know another workaround?
10 Apr, '21
Kirus
I am also experiencing this issue.
Windows 10, v1909

All DNS related traffic stops working.
21 Sept, '21
Dario
I have the same problem, i have been having it since game launch.
I am using a Zyxel modem if that matters anything. I had to do a quick setup for my internet settings in my modem settings thing and only after that i think it fixed itself.
THIS NEEDS TO BE FIXED VERY SOON !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
This has been a issue since launch for me!!
21 Feb, '22
Lifty
I also have the problem where as i start Valheim and try to connect to my friends Server it completely stops my PCs network traffic. I have a feeling it's because of an insane amount of requests sent to and by all other community servers that are available? Akin to a DDOS attack, whenever you launch the game by the sheer amount of requests being sent and received...

In any case this needs to be fixed immediately, a network issue like this needs to be #1 Priority... the fact it has been a thing for months is insane to me.
09 Dec, '22
Renegrade
I've been getting the same or a similar issue. After connecting to my dedicated server on another machine on my network, I lose the ability to initiate other connections to hosts not on my LAN. Packet capture shows SYN packets going out, but no response. While this is going on, other machines on my network are still fully operational so it's not like it's bringing down my modem or router. I don't see excessive bandwidth utilization anywhere.

The weird thing is that the external connections start working again in a couple of minutes.

Clearly this has to be some sort of Windows network stack or driver issue, but no other software triggers this problem and that makes it very hard to diagnose/isolate. Knowing about any network utilization oddities that are unique to Valheim would help enormously.
15 Dec, '22
Obby
I've recently been having these issues as well, never had them before. gonna try the suggestions above and see if that helps
15 Dec, '22
FloSho
Yo!
Got this problem aswell in valheim mistlands update.
Only when 2 or more try to connect to a server from the same routher.
18 Dec, '22
Renegrade
Update: I've discovered that there's a storm of packets going back and forth related to some sort of "TSource Engine Query" queries. My machine sends these queries to THOUSANDS of different remote IPs and gets responses back from them. It looks like it's getting server names from thousands of remote machines.

The problem is that my network router, a Cisco 1921, only supports 2048 NAT mappings per host, and each query creates a new mapping, rapidly exhausting it. Manually clearing the mappings solves the problem (plus they expire on their own over a few minutes).

host 10.0.0.8: max allowed 2048, used 138, missed 6652 <--- dedi server
host 10.0.1.1: max allowed 2048, used 2048, missed 497461 <--- my machine, active
host 10.0.1.3: max allowed 2048, used 16, missed 196033 <--- wife's machine, inactive

I'm connecting directly through favorites, not using the public lists.

NB: other machines aren't impacted as it's a per-machine limit.
18 Dec, '22
Renegrade
I don't know if this can be fixed for people using the public server list, but surely when the Favourites list is used, it should only query the servers on that list (of which I have like two and they're both on the LAN), not all public servers. That would prevent overloading the NAT table for people using the Favourites list (unless they had thousands of servers saved to Favourites)...

I've resolved the issue on my end by increasing the maximum mappings from 2048 per host to 32768, and giving UDP mappings a 15-second timeout. However, most consumer devices won't afford such control over the number of mappings or timeouts, so I'd strongly recommend avoiding doing those queries until or unless they are absolutely needed.
20 Dec, '22
John
I bought a server for my friends and I to play on for the Mistlands update and started running into this issue. I would launch the game and play for ~5 minutes before I would get disconnected and my internet would shut off (websites won't load, wifi turns off on my phone, etc.).

I decided to test it for myself so I used the CMD ping while running Valheim and sure enough, it was when I connected to my server. I came across this thread and saw the post from 'looz' suggesting self-ddos.

Finally fixed it by going into Steam settings > In-Game > 'Server Browser Pings / Minute' and turning it down to 500. I haven't had any issues since then but I hope they decide to eventually look into this and fix it.
25 Dec, '22
Amidas
Having this issue as well now. Never had it until today. Playing private server with someone on the same network as I am, able to play for a few minutes then my entire internet shuts off, but modem is on, and everything looks ok.
06 Jan, '23
Kendall
I have this issue too. I get kicked from my wifi anytime I play this game and have to run troubleshooter to reconnect my pc to the wifi. Please help!
07 Jan, '23
Tonino
I have this issue. Whenever I attempt to connect to any multiplayer server, my entire network goes down. Not just the ethernet connection on my computer, every device on my wifi loses internet connectivity for a couple of brief seconds and then it reconnects.
15 Jan, '23
Mick
Has this issue been forgotten? I only recently stated playing Valheim but I frequently experience this problem and is always and only with Valheim.
08 Feb, '23
Kev
I'm honestly surprised this is still an issue. I've reached out to Irongate support, the Reddit page, and even through the Steam Community. I've gotten no responses back, and it ruins my server.
20 Nov, '23
iu
I have the same problem, Valheim kills my router.
02 Mar
Niels
I also still have this issue. whenever I start the valheim server... my internet is having problems.
10 Apr
Mike
I have the same Valheim network crash problem in April of 2024, so this issue has still not been resolved. I tried changing the Steam Settings / In Game / "Server/Browser pings/minute" to 250 and still did not fix the issue. I am using Plume pods for my home network. Maybe only certain brands of devices are affected.
10 Apr
MaCarBre Admin
@Mike

Valheim has certain send rates set so that vast majority of players can run it on their modems.
Setting higher send rates is required when more players play, and when mods are used, however doing that will inevitably crash certain modems that won't be able to handle the increase in network traffic.
Setting those send rates lower will increase stability, but it will lead to more lag.
Certain weak modems can already crash on default send rates that Valheim set by Valheim, and unfortunately this can't be easily solved.

In order to set send rates higher or lower, this is currently only possible via mods.
In the future Valheim might give players the ability to set those send rates, so they can tweak them depending on their need.

One useful test that you can do, is the buffer bloat test. The test must be performed when no other applications are running on your system.
Let me know what kind of result you get: https://www.waveform.com/tools/bufferbloat