IPv4 vs. IPv6
IPv4 stands for Internet Protocol version 4 whereas IPv6 stands for Internet Protocol version 6. Both are used in the network layer of the TCP/IP model. The basic differences between the two are as follows:
1. IPv6 has more capacity than IPv4
The number of address bits in IPv6 are 128 with a capacity of 2^128 as compared to 32 in IPv4 with a capacity of 2^32.
2. IPv6 is more secure compared to IPv4
IPv6 provides authentication option to its users so that the packets sent over the internet are more secured.
3. IPv6 has flexible extensions and options compared to IPv4
It simplifies the packet header (containing address fields) by migrating the options (like fragmentation, etc.) to the extension header (with all other services like authentication, source routing, etc.).
4. IPv6 solves the problem of NAT (Network Address Translators) in IPv4
NAT that maps multiple private address spaces to a single public IP address and exposes the network to security threats have been removed from IPv6.
5. IPv6 ensures packet flow identification
The IPv6 uses a flow label field in the header and helps in packet flow identification as compared to IPv4 that has no packet flow identification scheme.
6. IPv4 is simpler and less complex as compared to IPv6>
Thus in many ways IPv6 is better than IPv4 but why have people not moved to IPv6? The answer is simple. IPv4 systems make use of less memory and less programming compared to IPv6 and also the address of IPv4 are simpler to remember because of the fewer bits allocated to them.
7. We are more familiar with IPv4 as compared to IPv6
Another reason why we consider IPv4 over IPv6. The existing infrastructure of IPv4 support itself in many levels already with every Network and System Administrator familiar with it today. However, this would definitely change in the days to come.
Both IPv4 and IPv6 have pros and cons but the demand of the future generation is of more and more addresses with the revolutionizing of Internet. Therefore, IPv6 is here to come sooner than later and stay in the longer run.