FAQ-IPV6# INTERVIEW PREP GUIDE ABOUT IPV6
'Practical term used in professional training'
🔹 How many bits are in an IPv6 address ?
128 Bits.
🔹 How many addresses does IPv6 provide ?
Approximately 340 undecillion (2¹²⁸) addresses.
🔹 What is the format of an IPv6 address ?
Hexadecimal format separated by colons.Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334
🔹 How many blocks are in an IPv6 address ?
8 Blocks.
🔹 How many bits are in each IPv6 block ?
16 bits (4 hexadecimal digits per block).
🔹 Can IPv6 have leading zeros ?
Yes, leading zeros can be removed.Example: 0db8 → db8
🔹 What is the double colon (::) in IPv6 ?
It represents consecutive blocks of zeros.Example: 2001:db8::1.
🔹How many times can :: be used in one IPv6 address ?
Only one time.
🔹 What are the main types of IPv6 addresses ?
Unicast, Multicast and Anyast.
🔹 What is a unicast address ?
Identifies a single interface.
🔹 What is a multicast address ?
Identifies a group of interfaces.
🔹 What is an anycast address ?
Assigned to multiple devices, but packet goes to nearest one.
🔹 Does IPv6 support broadcast ?
No, IPv6 does not use broadcast.
🔹 What is the loopback address in IPv6 ?
::1
🔹 What is the unspecified address ?
::
🔹 What is link-local address ?
Used for communication within the same network segment.Range: FE80::/10.
🔹 What is global unicast address ?
Public IPv6 address routable on internet.
🔹 What is unique local address (ULA) ?
Private IPv6 address. Range: FC00::/7.
🔹 Does IPv6 use NAT ?
Generally no, NAT is not required.
🔹 What is auto-configuration in IPv6 ?
Devices can configure themselves automatically (SLAAC: Stateless Address Auto Configuration).
🔹 Does IPv6 support IPSec ?
Yes, IPSec is built-in support.
🔹 What is the IPv6 header size ?
Fixed 40 bytes.
🔹 What is Neighbor Discovery Protocol (NDP) ?
Replaces ARP in IPv6.
🔹 What is the minimum MTU in IPv6 ?
1280 bytes.
🔹 What is IPv6 prefix length ?
Indicates network portion (e.g., /64: Its standard subnet size).
🔹 How many hosts in /64 ?
2⁶⁴ addresses.
🔹 What is dual stack ?
Running IPv4 and IPv6 together.
🔹 What is tunneling and NAT64 ?
Encapsulating IPv6 inside IPv4 and Translates IPv6 to IPv4.
🔹 What routing protocols support IPv6 ?
OSPFv3, EIGRP for IPv6, BGP.
🔹 Does DHCP exist in IPv6 ?
Yes, DHCPv6.
🔹 What is stateless DHCPv6 ?
Provides additional info but not IP address.
🔹 What is global routing prefix ?
Assigned by ISP.
🔹 What is interface ID ?
Last 64 bits in /64 subnet.
🔹 What is EUI-64 ?
Method to generate IPv6 interface ID from MAC address.
🔹 What security improvement does IPv6 provide ?
Better IPSec integration and no broadcast attacks.
🔹 Why is IPv6 future-proof ?
Massive address space and improved routing efficiency.
