christos%astron.com@localhost said: > masklen == 128 = (16 * 8) > mask.s6_addr[masklen / 8] = mask.s6_addr[16] = oops, since in6_addr: A masklen of 128 is certainly legal, but in that singular case (masklen % 8) is zero so that the code in question is not executed. best regards Matthias