Hello, I had the same problem and symtoms as you. net4801 + 1411 vpn + corrupted mac on input.
I've upgraded to a current build a few minutes ago, I did not get any errors anymore. (If you decide to upgrade too and you use pppoe, don't forget to read www.openbsd.org/faq/current.html because spppcontrol became obsolete.) regards didier [demime 1.01d removed an attachment of type APPLICATION/DEFANGED which had a name of didier.wiroth.31190DEFANGED-vcf]