Download the [linode-auth-hook.sh](https://apps.andysh.uk/aheathershaw/letsencrypt-linode/src/branch/master/linode-auth-hook.sh) and [linode-cleanup-hook.sh](https://apps.andysh.uk/aheathershaw/letsencrypt-linode/src/branch/master/linode-cleanup-hook.sh) shell scripts and make a note of where you have downloaded them to.
**Please note:** Linode only deploy changes to their nameservers roughly every 15 minutes, so DNS records do not show up immediately. The authorisation script waits for 20 minutes after creating a record before exiting to allow the DNS records to be deployed before Let's Encrypt verifies them. Therefore this script can take some time to run. Once a certificate has been issued, renewals happen non-interactively.