Varnish Enterprise 6.0.18r2 is a bug fix release with no new features. It reverts a single change from 6.0.18r1 that introduced a regression, and all users running 6.0.18r1 are encouraged to upgrade.
The 6.0.18r1 release reworked the lifetime handling of the VSM cluster
used to track VSM clients (varnishstat, varnishlog, and friends).
That change turned out to introduce a regression that can leave VSM
clients in a crash loop. 6.0.18r2 reverts it; all other changes from
6.0.18r1 are retained. (VS issue #3252)