Arch Linux

Tominjishi

Member

Registered: 2025-02-20

Posts: 3

[SOLVED] Issue with TCP on local network (MiniDLNA and KDE Connect)

I installed Arch on my pc about a week ago and my knowledge on networks is quite limited. At first I just wanted to run MiniDLNA, but when that didn't work (listens on port 8200 and the web ui is accessible locally, but other devices still can't connect) after much troubleshooting, I gave up thinking that it's just that specific service that doesn't work. A couple days later I tried setting up KDE Connect, and after that didn't work either (phone and pc not discovering each other even when I try to add by IP), i realized it's a more global issue.

The same issue persists when the devices are connected to the phones hotspot, not just the wi-fi.
Confirmed with ss -tulnp that both MiniDLNA and KDE Connect have opened and are listening on the appropriate TCP/UDP ports.
Running Test -NetConnection for port 8200 from a windows device on the same network successfully pings the device but the TcpTestSucceeded returns as false.
Have also tested with tcpdump:

sudo tcpdump -i wlan0 -n port 8200

When I try connecting to MiniDLNA from the aforementioned windows device, it just returns this 1 line multiple times:

17:53:26.851293 IP 192.168.1.102.58303 > 192.168.1.103.8200: Flags [S], seq 1263034839, win 64240, options [mss 1460,nop,wscale 8,nop,nop,sackOK], length 0

Which I think means the system just doesn't respond to the TCP requests.

All firewalls are disabled (ipatbles.service, nftables.service, ufw.service - I think those are the only ones that had installed during the installation process). I use NetworkManager with wpa_supplicant for the network connection (used iwd with systemd-networkd before, didn't work either). In the router settings firewall and isolation is disabled and UPnP is enabled. No port forwarding either.

Would really appreciate any sort of help on this.

Last edited by Tominjishi (2025-02-21 06:49:27)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 75,418

Re: [SOLVED] Issue with TCP on local network (MiniDLNA and KDE Connect)

On the host:

ip a
ip r
nft list ruleset
iptables -nvL

and remotely

nmap -p 8200 192.168.1.103

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Tominjishi

Member

Registered: 2025-02-20

Posts: 3

Re: [SOLVED] Issue with TCP on local network (MiniDLNA and KDE Connect)

Yeah I'm a bit silly, it was nftables all along. I knew some initial ruleset was in place, but saw that the service was inactive, so I dismissed firewalls being the issue early on. Turns out it was still enabled and purging the ruleset / disabling nftables fixed the issues. My bad.