Syslog daemon (syslogd) is a server process running in the z/OS UNIX environment. System applications and components can use syslogd for logging messages of various priorities to local z/OS UNIX files or to other syslog daemons in the network. The different message destinations are controlled through rules defined in a configuration file called /etc/syslog.conf. The z/OS syslogd can also log messages received over the network from other syslog daemons.
Prior to z/OS 3.1, syslogd only supported network communication over UDP, which is an inherently unreliable transport protocol. If you need to cryptographically protect UDP traffic, you must use IPsec VPNs, which is somewhat uncommon for syslog daemons.
With z/OS 3.1 Communications Server, syslogd adds the ability to communicate with other syslog daemons over TCP connections, which are far more reliable than UDP and can easily be secured using AT-TLS.
The syslog daemon supports receiving and sending messages with octet-counted framing over TCP connections. With Communications Server APAR PH56548, the syslog daemon also supports receiving messages with non-transparent (traditional) framing. TLSv1.3 sysplex-wide session resumption.
Restriction: The syslog daemon does not support sending messages with non-transparent (traditional) framing over TCP connections.
Dependencies: Syslogd is an AT-TLS aware application. To secure messages received by syslogd over a TCP connection, an AT-TLS sever rule must be configured for the connection. To secure messages sent by syslogd over a TCP connection, an AT-TLS client rule must be configured for the connection.