Also known as DynDNS or DDNS.
Most people's home Internet connections have a dynamic IP v4 address, meaning that their address on the Internet changes pretty frequently. This makes it difficult to run a server like FedWiki, because from outside, you have to know the current address.
Dynamic DNS is a service that can address this situation. It will attach a domain name or host to your IP address, and you periodically provide the Dynamic DNS provider (in automated fashion) with your current IP address. This can either be a domain that you own (mydomain.wiki) or something supplied by the provider (myhost.dynamicdnsprovider.com or dynamicdnsprovider.com/myhost).
# Options
No-IP offers free dynamic DNS but requires you to confirm every 30 days. Unclear if automated approaches fit their TOS and/or are practical.
They used to have a deal with Netgear that avoided the confirmation but it looks like that's over 
.
*Pete's Referral Link for No-IP: noip.com *
It's nice when your router handles the Dynamic DNS updates, but if your router isn't set up to work with a specific provider you may need to run a script on a computer on your network to periodically inform the Dynamic DNS provider of your current public IP address.
Free services include:
Good overview by cloudns
* https://dynamix.run/
# Run your own
Seems it's possible to run your own (though you need to control one place with a static DNS). See here and, maybe better, here .
# See also
It can also be worthwhile to set up your own DNS server, but that's a different thing from setting up Dynamic DNS. Wiki pages with info about that: