Internet Protocol (IP)Security
IP security (IPSec) is built into IPv6. This provides confidentiality, authentication and data integrity. IPv4 packets may contain malware, therefore, main corporate firewall block ICMP packets. But ICMPv6 is permitted because IPSec can be applied to the ICMPv6 packet, but ICMPv6 is end-to-end encryption and integrity-checking with IPSec support. It also supports more secure name resolution with the secure neighbor discovery (SEND) protocol. With ipv6, two devices can build a secure tunnel between them without any user intervention.