-A INPUT -p icmp -j ACCEPT
# SSH
-A INPUT -p tcp --dport 22 -j ACCEPT
+# HTTP; uncomment for creating LetsEncrypt certificates in standalone mode.
+#-A INPUT -p tcp --dport 80 -j ACCEPT
+# SMTP (allowing for STARTTLS); necessary for mail server to mail server banter
# HTTPS in theory, in practice my second SSH port, see sshd_config
-A INPUT -p tcp --dport 443 -j ACCEPT
# SMTP (allowing for STARTTLS); necessary for mail server to mail server banter