You have recently joined a company as the network administrator. You have been asked to complete the configuration on the border routers for an automatic 6-to-4 tunnel between several IPv6 network domains. The commands that are currently configured on the routers are as follows:
ipv6 route tunnel
interface tunnel
ipv6 address
tunnel source
Which of the following additional commands is required to complete the configuration of automatic 6-to-4 tunnel on the border routers?
A. tunnel mode ipv6ip
B. tunnel mode ipv6ip 6to4
C. tunnel mode ipv6ip auto-tunnel
D. tunnel mode ipv6ip isatap
Explanation:
The correct answer is to use the tunnel mode ipv6ip 6to4 command to complete the configuration of an automatic 6-to-4 tunnel. This command requires the use of IPv6 unicast addresses that have the 2002::/16 prefix.
The types of tunneling mechanisms supported by IPv6 are:
• Automatic 6-to-4 tunnel
• ISATAP tunnel
• Manually configured tunnel
• GRE tunnel
Apart from using a tunneling mechanism, interoperability between IPv4 and IPv6 can be provided by using a dual-stack infrastructure or Network Address Translation-Protocol Translation (NAT-PT). A dual-stack infrastructure allows you to use both IPv4 and IPv6 addresses on the same router/host. NAT-PT is used to translate IPv4 addresses to IPv6 and vice versa.
The tunnel mode ipv6ip command should not be used to complete the configuration because this command specifies IPv6 as the passenger protocol and creates a manually configured tunnel.
The tunnel mode ipv6ip auto-tunnel command is not required to enable automatic 6-to-4 tunneling on the border routers. This command creates an automatic IPv4-compatible IPv6 tunnel between the routers.
The tunnel mode ipv6ip isatap command should not be used because this command creates an ISATAP tunnel.
Objective:
Network Principles
Sub-Objective:
Recognize proposed changes to the network