Cloud Firewall (hidden) rules?
Are there any specific rules being applied that are hidden to the user when they utilize the Cloud Firewalls for a given Linode? e.g. based off of some blocklists or some traffic signatures.
I enabled Cloud Firewall to try it out and did a generic 80/443 inbound allow all with outbound all
or essentially:
allow inbound 80
allow inbound 443
deny all inbound
allow all outbound
Then I discovered certbot was failing to update letsencrypt certificates and it was having time out issues and hinted at possible firewall problems.
I disabled the Cloud Firewall service and retried certbot and all of the certs updated successfully.
This isn't a breaking thing for me given that I've always used local iptables / firewalld to handle firewalls, but it would be cool to run firewall'ing off the Linode in the event iptables/firewalld breaks (e.g. misconfigured rule).
1 Reply
_Brian
Linode Staff
Cloud Firewalls only apply the rules that you set. There aren't any additional hidden rules applied, and they don't have functionality in place to detect signatures or use blocklists.
I looked at the firewall you had in place, and I'm not seeing anything that should have caused the issue you described.
Do you happen to have a copy of the error message from the certbot log?