Objective 1.05 Distinguish IPv4 Versus IPv6 Query Including Differentiating IPv4/6 Transport Versus IPv4/6 Query Type and Extrapolating When Different Query Types Will Be Used on Different Transports 302 Practice Questions (Page 2)

Questions 6–10

1. 6expert · hard

   A company is deploying a new service that will be accessed by clients on both IPv4 and IPv6 networks. The BIG-IP DNS administrator is configuring the DNS records. The service is available on both IPv4 and IPv6 addresses. The administrator wants to ensure that clients use the most efficient path. What is the best approach?

   • AReturn A records to IPv4 clients and AAAA records to IPv6 clients, based on the client's source address.
   • BReturn both A and AAAA records, and let the client choose based on its capabilities and preferences.
   • CReturn only AAAA records to all clients, and rely on NAT64 for IPv4 clients.
   • DReturn only A records to all clients, and rely on NAT64 for IPv6 clients.
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   A company has a BIG-IP DNS system that is configured with both IPv4 and IPv6 addresses. A client on a dual-stack network sends a query for a domain. The client's operating system is configured to prefer IPv6. The BIG-IP DNS system receives the query over IPv6 transport. What type of response will the BIG-IP DNS system provide?

   • AThe response will match the query type, which could be A or AAAA, regardless of the transport used.
   • BAn AAAA record only, because the query arrived over IPv6 transport.
   • CAn A record only, because the client is on a dual-stack network and needs an IPv4 address.
   • DBoth A and AAAA records, because the client is on a dual-stack network.
   Reveal Solution Discussion Select an answer first
4. 8foundation · easy

   What is a key difference between IPv4 and IPv6 packet headers?

   • AIPv6 headers include a checksum field, while IPv4 headers do not.
   • BIPv4 headers are fixed length, while IPv6 headers include a variable-length options field.
   • CIPv6 headers are fixed at 40 bytes, while IPv4 headers are typically 20 bytes but can be larger with options.
   • DIPv4 headers are 128 bits, while IPv6 headers are 32 bits.
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5. 9application · medium

   A BIG-IP DNS administrator is configuring a new DNS listener. The listener is set to listen on an IPv6 address. A client on an IPv4-only network sends a DNS query to the BIG-IP system. What will happen?

   • AThe query will be received over IPv6 transport, and the BIG-IP system will respond with an AAAA record.
   • BThe query will be dropped because the listener is only on IPv6 and the client is on IPv4.
   • CThe query will be received over IPv4 transport because the client is on an IPv4-only network, even though the listener is on IPv6.
   • DThe query will not reach the BIG-IP system because the client on an IPv4-only network cannot send packets to an IPv6 address.
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6. 10expert · hard

   A BIG-IP DNS administrator is investigating a security incident. The logs show that a client sent an AAAA query over IPv6 transport and received an AAAA record. However, the client then attempted to connect to the IPv6 address in the record, and the connection was blocked by the firewall. The administrator suspects that the client is trying to bypass security controls. What is the most likely reason the client sent an AAAA query?

   • AThe client is trying to use IPv6 to bypass the firewall, which is why it sent an AAAA query.
   • BThe client's application is using an IPv6 socket, so it queries for AAAA records to get an IPv6 address.
   • CThe client is using a VPN that only supports IPv4, so it needs an IPv6 address to bypass the VPN.
   • DThe client is using a DNS proxy that converts A queries to AAAA queries.
   Reveal Solution Discussion Select an answer first