Quote ( ModMatK)
We are aware of the increased disconnection issues you have faced over the last few days along with the ongoing issues. The matter is with our ISP, but there are lots of moving parts to this issue so the solution is not a simple one.
As soon as we have some news that we can share with you we will.
I'm sorry we can't be more specific about it all at the moment.
Edit to add
If you're affected, it'd also be useful if you could perform a tracert and DM me the results (don't post it publicly here). To do this, you can follow the instructions found here, replacing world1.runescape.com with oldschool1.runescape.com, or whichever world you are having issues on.
Edit 22:49
I've just had an update from the sysadmin guys, the disconnections seem to be ddos related and in there words "we need to collect some more telemetry and then work on some improvements to mitigate them".
To give you a bit more of an oversight, ddos attacks are not just about sending loads of traffic to overwhelm a connection. There are many different types of attacks which evolve and develop over time and we are committed to overcoming each challenge when we face a new one.
Quote ( JagexSupport)
Hey!
Mod Cheryl here. We're aware of some connection problems and worlds that have headed offline. It's being investigated as we speak, but I wanted to make sure you're all aware that we know.
We'll be keeping our Support Center (especially this article) updated with any changes.
I've also posted this over on /r/runescape. But I wanted to post separately here to confirm this issue*(see edit) isn't related to /u/modmatk's post earlier today (especially since that post is so fresh).
Thanks for your patience, we're working hard to make sure you can get back to 'Scaping as soon as possible.
- Mod Cheryl
Edit; To update you all, it's been confirmed the cause was due to a major power issue at our Frankfurt Data Centre. To ensure they're stable, affected worlds will remain offline while full power is restored.
Edit 2; To answer what some of you are asking. Its quite possible that there has also been DDoS activity in other worlds seeing problems, but the mass kicking / worlds going offline (and staying offline) / being unable to access our web pages from some locations was caused by the power failure. If you're having problems on currently online worlds, /u/ModMatK's stickied post still stands.
Looks like Jagex is confused too.