- Configurable user-agent with version string placeholder (%V?)
- HTTP proxy authentication
+
+- Add curl HTTP headers to disable proxy caching
+
+- On too many update errors: Configurable block period and error threshold counter
+
+- Log alternative server name on successful/failed update
+
+- Clear external warning on successful update
+
+- Configurable CA certificate handling
+
+- Determine hostname TTL via DNS and remove option from config file
+
+Nice to have:
+- webcheck mode: Cache last known IP
+
+ We only determine the current IP every "webcheck_interval" to prevent server trashing.
+
+ If a service can't be updated right now (because the update interval forces an idle period),
+ it will only be updated after the next successful webcheck IP determination.
+ We could cache the last known IP and update the service as soon as
+ the service's update interval permits.
+
+- Move curl_* handling to own class/use HTTPHelper in ip_addr_helper
+
+- Add option to send out updates f.e. once a week as a kind of keepalive message.