Error 4001

Path from germany to SE's servers:

Pretty sure it doesn't matter but
Do you use the NA client?

caved and setup a VPN, went from r0ing to a 4001 like once an hour to nothing.

Told you it would work. :)

Greetings Blue Mage Draylo,

[GM] Malthar here. Hope you're having a fine day.

Is your VPN rotating your IP? If so, you may have to pay a little extra to get a static IP.

Why does it work?

Does anybody have a solution to this that does not involve a VPN? I've tried the VPN but it creates issues with other things that I'm doing in tandem with XI making it an unhelpful solution. This issue creeps up every-so-often and it's very annoying. It's been about 6 months since I've seen it, but now it's back with a vengeance! It used to only happen later at night, but now it's all hours.

From `tracert 124.150.152.209`, it looks like I have 5 real sections of the 24-node trip:
* Home to Comcast (13ms)
* Comcast to cogentco.com in Dallas (5ms)
* Within cogentco.com (50ms, deterministically bouncing around US cities)
* cogentco.com US to cogentco.com Tokyo (100ms)
* To/within SE (5ms)

It's no surprise that the trip across the ocean is the heavy hitter, but randomly losing 50ms bouncing around the US is a bit weird. Apparently tracert can be a bit unreliable with these providers because they deprioritize responding to ICMP traffic, but /shrug. It matches my observed UDP response times per wireshark and squinting.

To answer my own question, my understanding from googling it is that it's just an enterprise ISP effect. When you use a VPN, you're obviously using their ISP. They are surely paying for a enterprise ISP service, so instead of your normal ISP routing, you get:
* Whatever normal ISP routing to the VPN server
* Your VPN's Enterprise ISP routing to the exit point
* Local routing from the exit point to your destination

So it may make it faster, but it may make it slower depending on whether your local ISP sucks and how far out of the way your VPN's server is. I have to imagine that for me it would decrease ping, but 50ms in FFXI isn't really worth the hassle.

I don't, but if you tweak your config, you should be able to send only traffic from PlayOnline/XI apps over the VPN.

Alternatively, or if your VPN doesn't support split tunneling, you can approach it from the destination end of things and specify that only connections to SE's domains go via VPN.

No one has figured it out and when I kept recommending a VPN it was hinted I was a snake oil salesman... /shrug

Just nobody wants to pay even more monthly to fix a stupid problem, thankfully I took my friends VPN since it allows like 4 devices or something and they only use it for Netflix or whatever lol. It was so annoying, I was contemplating just taking a break lol I can imagine if someone is going thru this they would just quit. It was happening constantly, and not even just while afk, sometimes it would boot me mid instance for stuff.


I dont think so, i just have it set to USA and its been doing its thing. I am on verizon fios, which is suppose to be the best here. And I am directly connected to the router with cable. They arent that great imo, playing sparking zero online I get a lot of lag occasionally but this only started happening to XI in the past year. Altho I am over 50 stories into the sky, so they use a separate box to get connection up here, maybe its related

Given the mechanism I proposed above, you can probably get comparable performance/stability gains by bouncing your traffic off an AWS or GCP instance in the nearest data center. However, that would probably be more expensive than paying for a VPN and you'd have to self-manage, which sucks!

I'm close enough to one of their datacenters that supports it that I might try it using an e2-micro from GCP (always-free tier) as a traffic forwarder to see if it improves things. Given FFXI's diminutive traffic, it should be sufficient and ~free if I set it up correctly. Will report back if I actually get time to try it.

While it's true that just using a VPN can change your route and avoid problem nodes, there are other potential mechanisms. If you're using the VPN over TCP, any traffic that drops between you and the VPN will be resent automatically. So, if your VPN has a stable connection to SE's servers you can gain stability even if your connection to the VPN is unstable. In that case I'd recommend the nearest VPN to servers(one in Japan).

UDP over TCP is generally ill-advised because it can hinder speeds, but in this case the loss is basically nonexistent. It's another consideration.

It's also possible your ISP has a less than optimal BGP configuration and you're getting poor routing options for specific destinations.

if that is the case then apparently Verizon Fios, Spectrum and Google Fiber have sh\tty BGP configurations