From abnf_regexp.py#110 should be changed from `IPv6_RE = '(({0})|({1})|({2})|({3})|({4})|({5})|({6})|({7}))'.format( *variations )` to `IPv6_RE = '(({0})|({1})|({2})|({3})|({4})|({5})|({6})|({7})|({8}))'.format( *variations ) ` So, the rule ># [ *6( h16 ":" ) h16 ] "::" could be applied