Hello everyone,
Every few days, I get the following error message.
2026-05-27 19:42:43 CONNECTION_ERROR Connection error (2620:fe::fe#53): TCP connection failed while receiving payload length from upstream (Connection prematurely closed by remote server)
Additional info:
- Pi-hole is running on my Synology 723Plus
- The Synology is only accessible locally, no ports are forwarded to the outside
- Router: Fritzbox (with DS Lite tunnel)
I'm not an IT expert.
Can anyone help me?
"Connection prematurely closed by remote server", means the remote server (the upstream server used by Pi-hole - Quad9, in this case) closed the connection without any warning or return code.
If the upstream server closed a connection, there is nothing you can do to change that. Pi-hole is just warning that this happened and nothing was received.
This is normal and happens from time to time.
Does it make sense to switch upstream servers?
Are there any that don't have this problem?
Which ones have you had good experiences with?
I see messages like this with any upstream server.
Some servers (like using local Unbound with certain options) cause more messages like this than other servers, but eventually, this will happen with every server.
As I said, this is normal. No need to be worried or use a different server.
If you don't like to see messages like this, you can hide these messages if you enable misc.hide_connection_error option:
