Are you having lag issues with Diablo III in both single-player and multiplayer scenarios? Has the lag made the game unplayable? Apparently, you're not alone, as the "major lag" complaints that sprouted up over the weekend have caused Blizzard to open up an investigation into the issue. The network engineers are now asking players to supply some information in this sticky update.
"We'd like to have your trace route info when you trace to 188.8.131.52," said support agent Omrakos. "We'd also like to see the results when you run our Looking Glass utility to see the return path of the trace from Blizzard to you. Be sure to select Diablo III in the utility. And lastly, please identify your ISP and geographical location in your reply post with the above info."
Instructions to perform a trace route are listed here for both Windows PC and Max OS X gamers as well as the IP address of Blizzard's Diablo III server for the Americas. Using the trace route on a Windows machine includes accessing the CMD window, running it as the administrator, and typing "tracert" along with the destination server's IP address. In the case of Diablo III in North America, that number will be 184.108.40.206 as Omrakos states.
The instructions note that customers performing the trace route may see several hops later in the path that return a "Request Timed Out" or "Destination Net Unreachable" error. If their labels end in attens.net, att.net, alter.net, telia.net, then these are likely Battle.net servers, and users can ignore the error messages. These errors are likely the results of "safeguards" that protect the Battle.net servers.
Blizzard customers not wanting to fool around with the CMD option can instead use Looking-Glass to supply the needed data. This is a network diagnostic tool that allows users to ping the Battle.net Authentication server; the Battle.Net websites; and the servers for Diablo III, World of Warcraft, StarCraft II and Hearthstone. The available tests include MTR, Trace Route and Ping.
The current lag issue could be seen as a good example of why Diablo III needs to have an offline mode in the single-player experience. Blizzard has stressed time and time again that the online requirement is baked into the game's core and provides a number of cool features that can only be delivered by an Internet connection, such as local chat. Regardless, the online requirement may be seen by most Diablo III players as a form of DRM.
Should Diablo III have an offline mode? Blizzard will never cave in to that request, but it doesn't hurt to dream.