2.7 Describe IPv6 Transition (NAT44, NAT64, CGNAT, MAP-T and DS Lite) 350-501 Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   Which statement best describes how CGNAT differs from a typical home router NAT?

   • ACGNAT is designed to handle a much larger number of concurrent translations and subscribers
   • BCGNAT translates IPv6 to IPv4, while home router NAT translates IPv4 to IPv4
   • CCGNAT uses stateless translation while home router NAT is stateful
   • DCGNAT is deployed on customer premises equipment, while home router NAT is in the provider core
   Reveal Solution Discussion Select an answer first
2. 17expert · hard

   A service provider is evaluating MAP-T for IPv4-as-a-service. The provider's CPEs are MAP-T capable and will be assigned an IPv6 prefix that encodes a share of a public IPv4 address and a port range. The provider wants to ensure that a subscriber can host a small web server on a specific port. What is the key limitation the provider must communicate to the subscriber?

   • AThe subscriber must use a different IPv4 address for each service.
   • BThe subscriber must use DS Lite instead for inbound services.
   • CThe subscriber can only use the ports that are algorithmically assigned to their IPv6 prefix.
   • DThe subscriber must run a stateful NAT on their CPE.
   Reveal Solution Discussion Select an answer first
4. 18application · medium

   An ISP is migrating its access network to IPv6-only but has a large base of subscribers whose CPEs only support IPv4. The ISP wants to continue providing IPv4 Internet access to these subscribers by tunneling their IPv4 traffic over the new IPv6 access network. The CPE will encapsulate IPv4 packets in IPv6 and send them to a central concentrator in the ISP's core. Which mechanism does this describe?

   • ADual-Stack Lite (DS Lite)
   • BMAP-T
   • CNAT44
   • DNAT64
   Reveal Solution Discussion Select an answer first
5. 19application · medium

   A service provider is deploying MAP-T. The provider assigns each subscriber an IPv6 prefix that encodes a public IPv4 address and a port range. A subscriber wants to run a game server that listens on TCP port 27015. The subscriber's assigned port range is 1024-2047. What is the outcome?

   • AThe subscriber cannot host the game server on port 27015 because it is outside the assigned port range.
   • BThe subscriber must use a different IPv4 address for the game server.
   • CThe subscriber must configure a static NAT mapping on the CPE.
   • DThe subscriber can host the game server on port 27015 because MAP-T allows any port.
   Reveal Solution Discussion Select an answer first
6. 20application · medium

   An ISP has deployed DS Lite to serve IPv4-only subscribers over an IPv6-only access network. A subscriber reports that they can browse the web but cannot play an online game that requires incoming connections from other players. What is the most likely cause of this issue?

   • AThe subscriber's CPE is not IPv6-capable.
   • BThe B4 element is not encapsulating the game traffic correctly.
   • CThe AFTR is performing NAT44, which prevents unsolicited inbound connections to the subscriber.
   • DThe AFTR is not performing DNS64.
   Reveal Solution Discussion Select an answer first