Cisco CCDE 400-007 New Questions

Company ABC uses IPv4-only. Recently they started deploying new endpoint devices. For operational reasons, IPv6 cannot be disabled on these new endpoint devices. Which security measure prevents the new endpoint from learning an IPv6 prefix from an attacker?

Which issue poses a challenge for security architects who want end-to-end visibility of their networks?

Which component of the SDN architecture automatically ensures that application traffic is routed according to policies established by network administrators?

Company XYZ has designed their network to run GRE over IPsec on their Internet-based VPN to connect two sites. Which IPsec tunneling feature can they enable to optimize the data flow while ensuring that the headers contain no duplicate IP addresses?