Troubleshooting Guide

After starting the syslog server, to ensure authentication, you must setup a remote port forwarding
connection to connect the switch with the remote SSH client or the remote TLS server.
Secure syslog using SSH:
The syslog server is installed on a host that serves as SSH client. The SSH client requests a
connection with the SSH server that resides on the switch. A remote port forwarding connection,
called secure-forwarding, gets established between the syslog server and the switch. The syslog
server now listens for the log messages on the port 601 at the end of the secure channel. The
syslog server decrypts the received log messages and either stores or displays the messages.
Secure syslog using TLS:
The syslog server is installed on a host that serves as TLS server. The switch plays the role of a
TLS client. A TLS handshake is initiated between the syslog server and the switch. The syslog
server transmits a certificate which has subject common name and optional subject alternative
name (SAN). Subject common name is always present in the certificate but SAN is optional. The
server-cert-name must match with SAN name if present in the certificate else if SAN name is not
present, it must match with the Subject Common Name else TLS negotiation fails and the
connection to the server is closed. If the server-cert-name part is not configured, then the check is
not done.
Once the TLS handshake is successful, the log messages sent from the switch to the syslog server
are encrypted. The syslog server decrypts these messages using a private key. The server then
stores the messages or forwards them to other servers.
Supported syslog servers:
This feature supports the following syslog servers:
• For SSH tunneling — WinSyslog, which is the Windows OS based syslog server.
• For TLS tunneling — Rsyslog, which is a Linux based open source syslog server.
Simple Network Management Protocol
The Simple Network Management Protocol (SNMP) provides facilities to manage and monitor
network resources. SNMP consists of:
• Agents—An agent is software that runs on a device that maintains information about device
configuration and current state in a database.
• Managers—An SNMP manager is an application that contacts an SNMP agent to query or
modify the agent database.
• The SNMP protocol—SNMP is the application-layer protocol SNMP agents and managers use
to send and receive data.
• Management Information Bases (MIB)—The MIB is a text file that specifies the managed
objects by an object identifier (OID).
Simple Network Management Protocol
January 2017 Troubleshooting 39
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