Cloudflare uses Anycast technology, which means that our IP addresses point to many servers. We currently have 310+ data centers worldwide, which all serve your site and DNS. The requests will be route to different data centers, not some fixed data centers. Visitors will typically reach the data center closest to them which makes our network very fast: See http://www.dnsperf.com/. You can read more about Anycast at A Brief Primer on Anycast and Load Balancing without Load Balancers.
In some case, when the closest data center is under heavier load or unavailable, we may manually route the traffic to other datacenters to maintain the performance of your website. The benefits of Anycast network is that if many requests are made simultaneously to the same server, the server may become overwhelmed with traffic and be unable to respond efficiently to additional incoming requests. With an Anycast network, instead of one origin server taking the brunt of the traffic, the load can also be spread across other available data centers, each of which will have servers capable of processing and responding to the incoming request. This routing method can prevent an origin server from extending capacity and avoids service interruptions to clients requesting content from the origin server. You can read more at What is Anycast? https://www.cloudflare.com/en-gb/learning/cdn/glossary/anycast-network/).
So how do you explain that clients located in Seoul area are connecting via data centers in Japan or Hong Kong? And it is not temporary, this situation lasts for weeks now. I can provide specific IPs or we can continue in support case: 01021928
