What is the difference between IPv4 and IPv6?

 Theme: IP Addressing  Role: Network Engineer  Function: Technology

  Interview Question for Network Engineer:  See sample answers, motivations & red flags for this common interview question. About Network Engineer: Designs and maintains computer networks. This role falls within the Technology function of a firm. See other interview questions & further information for this role here

 Sample Answer 


  Example response for question delving into IP Addressing with the key points that need to be covered in an effective response. Customize this to your own experience with concrete examples and evidence

  •  Addressing: IPv4 uses 32-bit addresses, allowing for approximately 4.3 billion unique addresses. IPv6 uses 128-bit addresses, providing for approximately 340 undecillion unique addresses
  •  Address Format: IPv4 addresses are written in decimal format, separated by periods (e.g., 192.168.0.1). IPv6 addresses are written in hexadecimal format, separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334)
  •  Address Types: IPv4 has three types of addresses: unicast (one-to-one), multicast (one-to-many), and broadcast (one-to-all). IPv6 has two types: unicast and multicast
  •  Address Configuration: IPv4 addresses can be assigned manually (static) or dynamically (DHCP). IPv6 addresses can be assigned manually, through stateless autoconfiguration, or through DHCPv6
  •  Header Size: IPv4 headers are 20 bytes long, while IPv6 headers are 40 bytes long
  •  Header Fields: IPv4 headers include fields such as version, header length, type of service, total length, identification, flags, fragment offset, time to live, protocol, header checksum, source address, and destination address. IPv6 headers include fields such as version, traffic class, flow label, payload length, next header, hop limit, source address, and destination address
  •  Fragmentation: IPv4 supports fragmentation at the network layer, where packets can be divided into smaller fragments. IPv6 does not support fragmentation at the network layer, instead relying on the sending host to perform fragmentation if necessary
  •  Security: IPv4 does not have built-in security features, although it can be secured through additional protocols like IPsec. IPv6 includes built-in security features through IPsec, providing authentication, integrity, and confidentiality
  •  Transition Mechanisms: IPv4 to IPv6 transition mechanisms include dual-stack (running both protocols simultaneously), tunneling (encapsulating IPv6 packets within IPv4 packets), and translation (converting IPv4 packets to IPv6 packets and vice versa)

 Underlying Motivations 


  What the Interviewer is trying to find out about you and your experiences through this question

  •  Technical knowledge: Assessing the candidate's understanding of networking protocols and their ability to explain complex concepts
  •  Problem-solving skills: Evaluating the candidate's ability to identify and address challenges related to IP addressing and network connectivity
  •  Adaptability: Determining the candidate's familiarity with the transition from IPv4 to IPv6 and their ability to work with both protocols
  •  Awareness of industry trends: Assessing the candidate's knowledge of the latest networking technologies and protocols

 Potential Minefields 


  How to avoid some common minefields when answering this question in order to not raise any red flags

  •  Lack of knowledge: Not being able to provide a clear and concise explanation of the differences between IPv4 and IPv6
  •  Confusion: Mixing up or incorrectly stating the key differences between IPv4 and IPv6
  •  Incomplete answer: Leaving out important details or failing to mention significant differences between IPv4 and IPv6
  •  Outdated information: Providing outdated or incorrect information about IPv4 or IPv6
  •  Lack of understanding: Not being able to explain the implications or advantages of IPv6 over IPv4
  •  Inability to adapt: Failing to mention the challenges or considerations when transitioning from IPv4 to IPv6
  •  Poor communication skills: Struggling to articulate the differences between IPv4 and IPv6 clearly and concisely

 Related

  Other questions asked for the Network Engineer in Technology function. View details for the Network Engineer here