Disabling old IP addresses

We’ve made some significant upgrades to the network infrastructure powering GitHub, and it’s time to turn off some of the old gear. We’ve updated DNS records to point at our new IP space, but continue to see a steady trickle of requests to IP addresses long since removed from DNS.

On Tuesday, November 5th 2013, at 12pm Pacific Time, we’ll stop serving all HTTP, Git, and SSH requests to IP addresses that aren’t returned from DNS queries for the following domains:

• github.com
• gist.github.com
• api.github.com
• raw.github.com
• ssh.github.com
• wiki.github.com
• assets.github.com

This won’t affect you if you don’t have any /etc/hosts entries for any of the above domains. However, if you’ve added github.com or any of the listed domains to /etc/hosts over the last few years, you’ll need to remove those entries or GitHub will stop working for you next Tuesday at noon. Take a quick look at your /etc/hosts and/or your Puppet/Chef manifests to make sure you’re ready to go!

Please note that our DNS servers are configured to automatically return the IP address of a random, healthy load balancer for queries for the above records. If you have an existing /etc/hosts entry, we highly recommend not replacing it, but rather removing it entirely.

Update: If you’re on Windows, you’ll want to check %SystemRoot%system32driversetchosts for anything matching github.com. If there are no entries there and you’re still seeing a warning on GitHub.com, please send your network administrator a link to this blog post!