It could be reasonable to extend sort to support a hexadecimal numeric sort. It already supports numeric (decimal) and human-readable with SI prefixes (2k, 1G).

Hexadecimal sort is already the same as alphabetic sort. The main problem with IPv6 addresses is that zeroes get truncated all over the place. :: could mean :0000: or :0000:0000:0000:. It's not impossible to solve by any means, but pure hexadecimal sort wouldn't work.

How often do you need to sort IP addresses to begin with?

When you have lots of addresses and subnets, and want to see which addresses goes into what subnet

especially since ipv6 can be multi-homed. on corporate networks you ended up with difficult configurations and need to figure out why the packets are going the wrong way frequently.

> Probably better in this case would be to have a small program that expands IPv6 addresses that you could then pipe into sort. That would be more in-keeping with the Unix Way™.

I went and wrote this and then realized you'd need two utilities. One to expand the addresses, and one to minify the addresses, so your pipeline would be:

    cat ipv6-addrs.txt | ipv6expand | sort -V | ipv6minify

vs

    cat ipv6-addrs.txt | sort -6

The unix philosphy is do one thing and do it well. Ideally sort does sorting very well, including sorting of ipv6 addresses. Ergo, sort should handle ipv6 address sorting.