I just have a domain with DNS at dreamhost and a dyndns cron-job (in my case running off my openwrt router, which forwards some ports to the pi). My ISP doesn'

I just have a domain with DNS at dreamhost and a dyndns cron-job (in my case running off my openwrt router, which forwards some ports to the pi). My ISP doesn't seem to block any ports or anything like that, nor have I ever had any such trouble in Norway (been through a few ISP's here)