Locking specific traffic to one WAN gateway instead of the failover gateway grou

[SimonKepp]

Hi,
Complete newbie here.
Yesterday I set up my first pfSense appliance, with the main goal of providing fail-over for my Internet connection. I have a primary Internet connection from my Cable TV provider with 300/50Mbps and unlimited traffic, and set up a 4G wireless modem as a secondary connection for redundancy. Yesterday while testing the setup, I didn't take into account, that my media server was performing a full backup to BackBlaze, while testing the fail-over, so I quickly exceeded my 10 GB traffic limit per month on the backup 4G  connection.
To prevent this from happening in a real  failure scenario, I would like to limit backup traffic to only use the primary gateway, instead of using the gateway group with fail-over to the secondary connection.
I assume, that this must be done by creating a new Firewall rule specifically for the backup traffic, and target that traffic to the primary gateway. So my question is, how do I best set up such a firewall rule? BackBlaze provides the following list of servers they use as targets:

https://help.backblaze.com/hc/en-us/articles/217664588-Backblaze-IP-Address-List

Do I have to create a rule with all the listed subnets, and maintain that everytime BackBlaze adds new targets, or is there anyway to define the target of the communication based on DNS suffixes such as *.backblaze.com or *backblazeb2.com

Thanks in advance,
Simon.

[Derelict]

You might ask them to put that list on their webserver it a plain-text format. That way you could just periodically update a URL type alias from their site.

Absent that, yes, you will probably need to keep the alias updated yourself.