You can overrride the Name Resolution with specific IP address without adding the hostname to /etc/hosts file by using --resolve option.

Syntax :

1

--resolve <host:port:address>

It will resolve IP address when connect to host on port

Example :

This will connect 127.0.0.1

1

$ curl --resolve google.com:80:127.0.0.1 "http://google.com/"

But this won’t connect 127.0.0.1, because we use 443 port for https

1

$ curl --resolve google.com:80:127.0.0.1 "https://google.com/"

For cover all ports, use * wildcard

1

$ curl --resolve google.com:*:127.0.0.1 "https://google.com/"

You can check the history of a domain (A Record). It’s useful in case you forgot the old IP of domain.

Check it here : http://viewdns.info/iphistory/

Example : this is Github A record history http://viewdns.info/iphistory/?domain=github.com

Too tired of setting your local domain each time you create new virtual development domain, etc helloworld.test, unit.test point to 127.0.0.1

There is a better way to achieve that by using dnsmasq, then set up a wildcard domains for development. In this case I use .test because .dev has been owned by Google and they strictly use HTTPS in mainly browsers.

Install dnsmasq

1

$ brew install dnsmasq

Adding .test wildcard to config file

1

$ echo 'address=/.test/127.0.0.1' > $(brew --prefix)/etc/dnsmasq.conf

Setup dnsmasq as a startup service

1

$ sudo brew services start dnsmasq

Then add 127.0.0.1 (dnsmasq IP) as first DNS resolver

1

System Preferences > Network > Wi-Fi > Advanced... > DNS > add 127.0.0.1 > move it to top of the list.

Checking everything is worked by listing all resolvers

1

$ scutil --dns

Try it out

1
2

$ nslookup -type=a something.test
$ ping helloworld.test

There are 2 simple ways to clear DNS cache on iOS devices :

1. (FASTER) Just enable the Airplane Mode, wait 10 seconds and disable it
2. (SLOWER) Reboot the device ! ;) You know this always be classic answer for many questions :D

We can get our external IP address by following ways :

1. Call http request : curl http://wtfismyip.com/text or curl http://ifconfig.me/ip
2. Lookup A record for hostname nslookup myip.opendns.com resolver1.opendns.com (this only works when you use resolver of OpenDNS)

Bonus : curl https://v6.ident.me/ for IPv6