Q. What are the advantages of IPV6 over IPV4?
IPv6 (Internet Protocol version 6) is the sixth revision to the Internet Protocol and the successor to
IPv4. It functions similarly to IPv4 in that it provides the unique IP addresses necessary for Internetenabled devices to communicate. However, it does have one significant difference: it utilizes a 128bit IP address.
Key benefits to IPv6 include:
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No more NAT (Network Address Translation)
Auto-configuration
No more private address collisions
Better multicast routing
Simpler header format
Simplified, more efficient routing
True quality of service (QoS), also called "flow labelling"
Built-in authentication and privacy support
Flexible options and extensions
Easier administration (no more DHCP)
IPv4 uses a 32-bit address for its Internet addresses. That means it can provide support for 2^32 IP
addresses in total around 4.29 billion. That may seem like a lot, but all 4.29 billion IP addresses have
now been assigned, leading to the address shortage issues we face today.
IPv6 utilizes 128-bit Internet addresses. Therefore, it can support 2^128 Internet addresses—
340,282,366,920,938,463,463,374,607,431,768,211,456 of them to be exact. The number of IPv6
addresses is 1028 times larger than the number of IPv4 addresses. So there are more than enough
IPv6 addresses to allow for Internet devices to expand for a very long time.
Q. Compare IPV4 and IPV6 header fields.
32-bits
IP 4 Header
Header
Type of Service (8)
Total Length (16)
Length (4)
Identification (16)
Fragment Offset (13)
Flag(3)
Time To Live (8)
Protocol (8)
Header Checksum (16)
Source IP Address (32)
Destination IP Address (32)
IP Options "optional" (24)
Padding (8)
Version (4)
32-bits
IP 6 Header
Version (4)
Traffic Classs (8)
Payload Length (16)
Flow Label (20)
Next Header (8)
Hoop Limit (8)
Source IP Address (128)
Destination IP Address (128)
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IPv6 header is much simpler than IPv4 header.
The size of IPv6 header is much bigger than that of IPv4 header, because of IPv6 address size.
IPv4 addresses are 32bit binary numbers and IPv6 addresses are 128 bit binary numbers.
In IPv4 header, the source and destination IPv4 addresses are 32 bit binary numbers. In IPv6
header, source and destination IPv6 addresses are 128 bit binary numbers.
IPv4 header includes space for IPv4 options. In IPv6 header, we have a similar feature known
as extension header. IPv4 datagram headers are normally 20-byte in length. But we can
include IPv4 option values also along with an IPv4 header. In IPv6 header we do not have
options, but have extension headers.
The fields in the IPv4 header such as IHL (Internet Header Length), identification, flags are not
present in IPv6 header
Time-to-Live (TTL), a field in IPv4 header, typically used for preventing routing loops, is
renamed to it's exact meaning, "Hop Limit".