Major new features are:
* **Multipath support** with modes modeled after the Linux kernel's bonding driver. This includes active-passive and active-active modes with fast failover and load balancing. See section 2.1.5 of the manual.
* **DNS configuration** push from network controllers to end nodes, with locally configurable permissions for whether or not push is allowed.
* **AES-GMAC-SIV** encryption mode, which is both somewhat more secure and significantly faster than the old Salsa20/12-Poly1305 mode on hardware that supports AES acceleration. This includes virtually all X86-64 chips and most ARM64. This mode is based on AES-SIV and has been audited by Trail of Bits to ensure that it is equivalent security-wise.
Known issues that are not yet fixed in this beta:
* Some Mac users have reported periods of 100% CPU in kernel_task and connection instability after leaving networks that have been joined for a period of time, or needing to kill ZeroTier and restart it to finish leaving a network. This doesn't appear to affect all users and we haven't diagnosed the root cause yet.
* The service sometimes hangs on shutdown requiring a kill -9. This also does not affect all systems or users.
* AES hardware acceleration is not yet supported on 32-bit ARM, PowerPC (32 or 64), or MIPS (32 or 64) systems. Currently supported are X86-64 and ARM64/AARCH64 with crypto extensions.
* Some users have reported multicast/broadcast outages on networks lasting up to 30 seconds. Still investigating.
We're trying to fix all these issues before the 1.6.0 release. Stay tuned.
