About System Message Logging
You can use system message logging to control the destination and to filter the severity level of messages that system processes generate. You can configure logging to terminal sessions, a log file, and syslog servers on remote systems.
For more information about the system message format and the messages that the device generates, see the Cisco NX-OS System Messages Reference.
By default, the device outputs messages to terminal sessions and logs system messages to a log file.
The following table describes the severity levels used in system messages. When you configure the severity level, the system outputs messages at that level and lower.
Level |
Description |
---|---|
0 – emergency |
System unusable |
1 – alert |
Immediate action needed |
2 – critical |
Critical condition |
3 – error |
Error condition |
4 – warning |
Warning condition |
5 – notification |
Normal but significant condition |
6 – informational |
Informational message only |
7 – debugging |
Appears during debugging only |
The device logs the most recent 100 messages of severity 0, 1, or 2 to the NVRAM log. You cannot configure logging to the NVRAM.
You can configure which system messages should be logged based on the facility that generated the message and its severity level.
Syslog Servers
The syslog servers run on remote systems that log system messages based on the syslog protocol. You can configure up to eight IPv4 or IPv6 syslog servers.
To support the same configuration of syslog servers on all switches in a fabric, you can use Cisco Fabric Services (CFS) to distribute the syslog server configuration.
Note |
When the device first initializes, messages are sent to syslog servers only after the network is initialized. |
Secure Syslog Servers
Beginning with Cisco NX-OS Release 9.2(1), you can configure the syslog server with support for a secure TLS transport connectivity to remote logging servers. Additionally, you can enforce the NX-OS switches (client) identity via the mutual authentication configuration. For NX-OS switches, this feature supports TLSv1.1 and TLSv1.2.
The Secure syslog server feature uses the TCP/TLS transport and security protocols to provide device authentication and encryption. This feature enables a Cisco NX-OS device (acting as a client) to make a secure, encrypted outbound connection to remote syslog servers (acting as a server) supporting secure connectivity for logging. With authentication and encryption, this feature allows for a secure communication over an insecure network.