IP address SOP for Linode

The only time your IP address will ever change is if you ask for it to be changed (and you need a good reason for this), you swap it with another one of your Linodes in the same datacenter (this is completely self-service), or you ask to be migrated to another datacenter (which requires a support ticket). Otherwise, your IP address will always be the same for the life of the Linode. The templates use DHCP because it's a very easy way to get network configuration without having to edit configuration files. That said, Network Helper (you can enable it in the configuration profile, and set whether it's enabled by default for new configuration profiles in the Account section) will write static network configuration files for you as part of booting your Linode. It exists mainly for convenience, though, so if you don't want to use it, you don't have to (I don't, for example, because I tend to do crazy custom stuff in my network configs).