FWIW, I see this too (net5501, netbsd-6 from about a month ago). I get 3-4 missing ping packets starting/stopping, and no problems with -p. This also happens on netbsd-5, but I don't see vr0 being different - it's consistently 3-4s. Probably a PR is in order, or asking on the soekris list. If this doesn't happen in OpenBSD or FreeBSD, then it's probably easy to grab the fix.
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