Not able to connect to peers on local discovery.

[forumcontributer]

I have two device and I want to sync some folders between them. But both devices don’t find to each other on local-discovery(Global turned off), unless I go to the device setting and manually type address of the other device. I tried to use hostname but it didn’t work. Even though I am able to ping other device using hostname. I am not quite familiar with Networking so pardon me.

Syncthing version: 1.28.1(Both) Linux.

[chaos]

The Local Discovery Protocol documentation is here: Local Discovery Protocol v4 — Syncthing documentation .

Given that ping works, and manual entry of the address works, my bet is that the local firewall on one or both of your Linux machines is preventing the reception of UDP/21027, or broadcasts, or multicasts.

Which specific Linux distros are you using? Is your network IPv4, IPv6, or both?

[forumcontributer]

Ubuntu 24.04

I am using both(IPv4 and IPv6) TCP.

Edit: @chaos You were right it was firewall.

Also does local-disco only work on ipv6? because in logs only ipv6 address was there not ipv6. Any way to make it use ipv4?

Thanks.

[chaos]

Local Discovery definitely works on IPv4. I have speculated that some network stacks seem to prefer IPv6 when both are available, but truthfully I haven’t tried to figure that out.

Go to Settings/Connections/Sync Protocol Address and see Syncthing Configuration — Syncthing v1.28.1 documentation . You can force Syncthing to use IPv4 here.