When IPv6 is active on an interface of an ISA Server 2004, it seems that IPv6 packets are not filtered and bypass the firewall. I try to send an ICMP IPv4 packet through the network to ISA Server, this packet was dropped, then i try an ICMP IPv6 packet which successfully works ! The same kind of test was successfull with a TCP connection using IIS 6 and IPv6. Romain Le Guen
