The examples for receiving from or sending to remote hosts in the default syslog-ng.conf include directives that aren't supported by the packaged version of syslog-ng.

From the default syslog-ng.conf:

=========================
<snip>

If you wish to get logs from remote machine you should uncomment

this and comment the above source line.

#
#source s_net { tcp(ip(127.0.0.1) port(1000) authentication(required) encrypt(allow)); };
</snip>

<snip>

Send the messages to an other host

#
#destination d_net { tcp("127.0.0.1" port(1000) authentication(on) encrypt(on) log_fifo_size(1000)); };
</snip>

If I try to start syslog-ng, for example, with the above source definition, I get the following message:

=========================
[....] Starting system logging: syslog-ngError parsing afsocket, syntax error, unexpected LL_IDENTIFIER in /etc/syslog-ng/syslog-ng.conf at line 28, column 45:

source s_src { tcp(ip(127.0.0.1) port(1000) authentication(required) encrypt(allow)); };
^^^^^^^^^^^^^^