Pete, a network administrator, is implementing IPv6 in the DMZ. Which of the following protocols
must he allow through the firewall to ensure the web servers can be reached via IPv6 from an IPv6
enabled Internet host?
A.
TCP port 443 and IP protocol 46
B.
TCP port 80 and TCP port 443
C.
TCP port 80 and ICMP
D.
TCP port 443 and SNMP
Explanation:
HTTP and HTTPS, which uses TCP port 80 and TCP port 443 respectively, is necessary for
Communicating with Web servers. It should therefore be allowed through the firewall.
Really? I’ve been told by numerous sources the answer is TCP port 80 and ICMP
ICMP must be allowed for successful IPv6 communications.
In IPv4, ICMP provides error reporting, flow control and first-hop gateway redirection. This functionality, which is also available in IPv6, is usually not essential to the operation of your network. With IPv6, however, ICMP has gained a much more significant and essential role because of new functionality that is now performed through ICMP. Fragmentation, Neighbor Discovery, and StateLess Address AutoConfiguration (SLAAC) represent essential functionality which is now performed using ICMP messages. Furthermore, many ICMP messages are designed to be sent to multicast addresses instead of only unicast addresses. Therefore, ICMP in IPv6 gains a whole new importance along with a new set of security concerns.
So I would say that CompTIA is probably looking for answer C !
See the article below:
http://blogs.cisco.com/security/icmp-and-security-in-ipv6