I go in charging with a full YES. The IPv4 address space is depleting, and depleting fast. Depletion has been anticipated since the late 1980s, and top-level exhaustion occurred on 24 September 2015 where four out of the five global authorities for passing out IPv4 addresses across the world exhausted their IPv4 addresses (according to Wikipedia ). IPv4 is NOT the future, it is a technology that only exists because we are dragging it along. It is dead weight. It will cost the Internet and everyone using it more money, because I imagine a scarce resource like an IP address will make the price of itself go up. This is also why I say you are supporting Internet freedom by supporting IPv6 as much as you can.
The IPv6 address space has approximately 3.4×10^38 addresses, whereas IPv4 only has less than 4,294,967,296. The IPv4 address space is a small number, considering that your smartphone, your home, your work, all your hobby servers each have its own IP address, and everyone else in the world. Now, we’re going to have freaking light bulbs, cars, toilets, fish tanks, and dogs that are each assigned IP addresses, and with companies expanding their networks to 3rd world countries and all the way out on farms (a farmer literally paid $383,500 to have fiber optic to his farm, so he could check grain prices - link ), there are a lot more people who are going to be added to our global, public network. The public internet is no longer a fun hobby, it is a need. With Wi-Fi protocols coming out that support unlicensed 900MHz (you can get slow 100kbps Wifi from 1-2 miles away), we will now be able to support street lights, electric meters, etc., which will all have IP addresses.
The other side of that is that there is Network Address Translation (NAT) that reduces the amount of public IP’s taken up in the world. Basically, if you don’t know already, your ISP doesn’t have (and doesn’t like to give) many public IP addresses to customers. Both IPv4 and IPv6 support private IP address blocks. What a private IP address is, is your router (DHCP server, to get technical) assigns every device in your house a private IP address. When your device connects to a public IP address, it goes through your router, to your ISP, and eventually to wherever it goes. To the rest of the world, your device is talking from a public IP address. So NAT turns a public IP into a private IP (going into the home network, from the outside world) if it is responding to outbound traffic (you must port forward otherwise), and a private IP into a public IP (when going out of the home network). I am NOT a networking guy, I just know enough to get by. Please look this particular one up, as NAT is fuzzy even for me. However, I know that NAT allows for households to live with just one IP address.
The other thing is that IPv4 and IPv6 don’t cross-over. You must either connect with one, or connect using the other. An advantage of having an IPv6-enabled server is that you can cater to the small amount of clients/servers that only support IPv6. For example, Vultr ( link ) has a package that makes it cheaper to go without an IPv4 address, which I imagine is appealing to some customers.
There are also some other technical advantages as well. I don’t understand them but here they are from https://www.networkcomputing.com/networking/six-benefits-ipv6 :
More Efficient Routing
IPv6 reduces the size of routing tables and makes routing more efficient and hierarchical. IPv6 allows ISPs to aggregate the prefixes of their customers’ networks into a single prefix and announce this one prefix to the IPv6 Internet. In addition, in IPv6 networks, fragmentation is handled by the source device, rather than the router, using a protocol for discovery of the path’s maximum transmission unit (MTU).
More Efficient Packet Processing
IPv6’s simplified packet header makes packet processing more efficient. Compared with IPv4, IPv6 contains no IP-level checksum, so the checksum does not need to be recalculated at every router hop. Getting rid of the IP-level checksum was possible because most link-layer technologies already contain checksum and error-control capabilities. In addition, most transport layers, which handle end-to-end connectivity, have a checksum that enables error detection.
Directed Data Flows
IPv6 supports multicast rather than broadcast. Multicast allows bandwidth-intensive packet flows (like multimedia streams) to be sent to multiple destinations simultaneously, saving network bandwidth. Disinterested hosts no longer must process broadcast packets. In addition, the IPv6 header has a new field, named Flow Label, that can identify packets belonging to the same flow.
Simplified Network Configuration
Address auto-configuration (address assignment) is built in to IPv6. A router will send the prefix of the local link in its router advertisements. A host can generate its own IP address by appending its link-layer (MAC) address, converted into Extended Universal Identifier (EUI) 64-bit format, to the 64 bits of the local link prefix.
Support For New Services
By eliminating Network Address Translation (NAT), true end-to-end connectivity at the IP layer is restored, enabling new and valuable services. Peer-to-peer networks are easier to create and maintain, and services such as VoIP and Quality of Service (QoS) become more robust.
IPSec, which provides confidentiality, authentication and data integrity, is baked into in IPv6. Because of their potential to carry malware, IPv4 ICMP packets are often blocked by corporate firewalls, but ICMPv6, the implementation of the Internet Control Message Protocol for IPv6, may be permitted because IPSec can be applied to the ICMPv6 packets.
EDIT: One more downside of IPv6 is that there are more addresses. This may have the same effect as printing money, the more you print (in this case, the more IP addresses you have available), the more it is worthless. Hackers now have more room to just switch their IPv6 address if they get caught on a blacklist, or want to just switch it for whatever reason. That isn’t to say that GeoIP (that is, associating their IP address with their location) doesn’t still exist, and that there are ways around it. Currently, if an attacker wants to change their IPv4 address, they can still do that easily (not AS easily though), so this is a weak argument anyways.