strelaysrv [-debug] [-ext-address=<address>] [-global-rate=<bytes/s>] [-keys=<dir>] [-listen=<listen addr>] [-message-timeout=<duration>] [-nat] [-nat-lease=<duration> [-nat-renewal=<duration>] [-nat-timeout=<duration>] [-network-timeout=<duration>] [-per-session-rate=<bytes/s>] [-ping-interval=<duration>] [-pools=<pool addresses>] [-protocol=<string>] [-provided-by=<string>] [-status-srv=<listen addr>]
- Enable debug output.
- An optional address to advertising as being available on. Allows listening on an unprivileged port with port forwarding from e.g. 443, and be connected to on port 443.
- Global rate limit, in bytes/s.
- Directory where cert.pem and key.pem is stored (default “.”).
- -listen=<listen addr>
- Protocol listen address (default “:22067”).
- Maximum amount of time we wait for relevant messages to arrive (default 1m0s).
- Use UPnP/NAT-PMP to acquire external port mapping
- NAT lease length in minutes (default 60)
- NAT renewal frequency in minutes (default 30)
- NAT discovery timeout in seconds (default 10)
- Timeout for network operations between the client and the relay. If no data is received between the client and the relay in this period of time, the connection is terminated. Furthermore, if no data is sent between either clients being relayed within this period of time, the session is also terminated. (default 2m0s)
- Per session rate limit, in bytes/s.
- How often pings are sent (default 1m0s).
- -pools=<pool addresses>
- Comma separated list of relay pool addresses to join (default “https://relays.syncthing.net/endpoint”). Blank to disable announcement to a pool, thereby remaining a private relay.
- Protocol used for listening. ‘tcp’ for IPv4 and IPv6, ‘tcp4’ for IPv4, ‘tcp6’ for IPv6 (default “tcp”).
- An optional description about who provides the relay.
- -status-srv=<listen addr>
- Listen address for status service (blank to disable) (default “:22070”). Status service is used by the relay pool server UI for displaying stats (data transferred, number of clients, etc.)
The relay server can also be obtained through apt, the Debian/Ubuntu package manager. Recent releases can be found at syncthing’s apt repository https://apt.syncthing.net/. The name of the package is syncthing-relaysrv.
$ sudo useradd strelaysrv $ sudo mkdir /etc/strelaysrv $ sudo chown strelaysrv /etc/strelaysrv $ sudo -u strelaysrv /usr/local/bin/strelaysrv -keys /etc/strelaysrv
This creates a user strelaysrv and a directory /etc/strelaysrv to store the keys. The keys are generated on first startup. The relay will join the global relay pool, unless a -pools="" argument is given.
To make the relay server start automatically at boot, use the recommended procedure for your operating system.
The relay’s device ID is output on start-up.
One option is to run the relay on port 22067, and use an iptables rule to forward traffic from port 443 to port 22067, for example:
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 22067
Or, if you’re using ufw, add the following to /etc/ufw/before.rules:
*nat :PREROUTING ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] -A PREROUTING -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 22067 COMMIT
You will need to start strelaysrv with -ext-address ":443". This tells strelaysrv that it can be contacted on port 443, even though it is listening on port 22067. You will also need to let both port 443 and 22067 through your firewall.
Another option is described here https://wiki.apache.org/httpd/NonRootPortBinding, although your mileage may vary.
- Data port: 22067/tcp overridden with -listen and advertised with -ext-address
- Status port: 22070/tcp overridden with -status-srv
Runtime iptables rules to allow access to the default ports:
iptables -I INPUT -p tcp --dport 22067 -j ACCEPT iptables -I INPUT -p tcp --dport 22070 -j ACCEPT
Please consult Linux distribution documentation to persist firewall rules.
|August 17, 2021||v1|