Checking availability of Launchpad frontends

Launchpad is using round-robin DNS to load balance requests among the frontends.

So in order to check the availability of the frontends, you need to get a list of all frontends and then check them individually.

Get list of frontends

$ host launchpad.net

launchpad.net has address 185.125.189.223
launchpad.net has address 185.125.189.222
launchpad.net has IPv6 address 2620:2d:4000:1001::8003
launchpad.net has IPv6 address 2620:2d:4000:1001::8004
launchpad.net mail is handled by 10 mx.launchpad.net.

Check individual frontend

$ curl --resolve launchpad.net:443:185.125.189.222 https://launchpad.net/

More infos on using curl.