Resolved
Slack identified this as a DNS issue, which is mostly resolved now. We're not seeing any further impact.
Monitoring
We're still keeping an eye on this. From our metrics it looks like the impact is minimal now, but we'll continue monitor the situation.
Monitoring
Slack are investigating reports of users being unable to connect. We're seeing some minor degradation leading to very occasional timeouts.
More details from Slack here: https://status.slack.com