I am using 10.1.0 on 7.6-release with Comcast (Xfinity), and haven't encountered the reported problem.
Lucky you then. I am the one that reported the problem because it exists. https://github.com/NetworkConfiguration/dhcpcd/pull/376 explains the issue, and a fix was pushed to master that works. master has a separate issue that requires reverting https://github.com/NetworkConfiguration/dhcpcd/commit/e3c5de14f01227f53b3fb87b76e1dd0e69722981 I have been running it for the past 3 weeks without issue. I also have Xfinity/Comcast as my ISP. Do you actually run dhcpcd _before_ network daemons like unbound(8) in rc(8)? I treat dhcpcd no differently than base daemons like dhcpleased(8) since I run daemons that require a working IPv6 and IPv4 address. If you start dhcpcd where daemons like dhcpleased(8) start, I wager you'll hit the issue. Presumably most don't run dhcpcd like I do; thus the timeout bug will likely not affect many. I would personally prefer if -stable were updated with master with the stated commit reverted; but if not, then I'll keep running my own version.
