Client Does Not Stay Connected

client
1

I am running UrBackup Server on an HP DL380 running Ubuntu Server 26.04LTS. I have several LAN connected clients that are backing up happily, and I had my fileserver working, but I may need to tweak its settings again as it is now showing off-line. The machine I am working on now is a remote server runing tailscale (free version). I have been struggling to get it to connect and run a backup. it will show in the web ui as connected and when I select “start full file backup” it queues. All good … then it fails. I have run logs and watched the system try to connect then fail. I have run tcpdump and the client completes the three way handshake, but then sits quite until the server times out at 30 seconds and sends a fin tag.

So the last thing the server/client does is request an upgrade to the websocket and the two agree on that, but then the client sends nothing, and after 30 seconds the fin tag.

This should work, it works for the clients on my class c network, it should work for this client.

I thought maybe a mismatch in the version the web ui shows 2.5.38 and the client is 2.5.30, but the 2.5 is the same, so that shouldn’t be the issue.

Any ideas are welcome at this point.

Rod

2

The 30 seconds aren’t random. Once an Internet client is connected, the server pings it and closes the connection if no answer comes within 30 seconds. That’s the FIN you see. So the client either never gets that data or can’t answer it. The server log (/var/log/urbackup.log, debug level) should show “Ping timeout in InternetServiceConnector::Run” or “ISS_RECEIVE_ENDPOINT timeout” around that time. The client’s debug.log would show its side.

Since Tailscale already puts both machines on the same network, you don’t need Internet mode for this client. Add its Tailscale IP on the server’s Status page (Add new client, discover a local/passive client across networks). The server then connects to it like one of your LAN clients, on ports 35621-35623, and the Internet mode handshake is out of the picture. Tailscale’s ACLs need to allow those ports.

2.5.30 vs 2.5.38 isn’t the problem. They use the same protocol.

3

Thanks for the quick response. Yeah, that makes much more sense. I will give that a try and see if I can get this client connected. I will post my progress.

Again, thanks!

Rod