Configure Syslog Monitoring

1. Configure a Syslog server profile.
   You can use separate profiles to send syslogs for each log type to a different server. To increase availability, define multiple servers (up to four) in a single profile.
   1. Select DeviceServer ProfilesSyslog.
   2. Click Add and enter a Name for the profile.
   3. If the firewall has more than one virtual system (vsys), select the Location (vsys or Shared) where this profile is available.
   4. For each syslog server, click Add and enter the information that the firewall requires to connect to it:
      • Name—Unique name for the server profile.
      • Syslog Server—IP address or fully qualified domain name (FQDN) of the syslog server.
        If you configure an FQDN and use UDP transport, if the firewall cannot resolve the FQDN, the firewall uses the existing IP address resolution for the FQDN as the Syslog Server address.
      • Transport—Select TCP, UDP, or SSL (TLS) as the protocol for communicating with the syslog server. For SSL, the firewall supports only TLSv1.2.
      • Port—The port number on which to send syslog messages (default is UDP on port 514); you must use the same port number on the firewall and the syslog server.
      • Format—Select the syslog message format to use: BSD (the default) or IETF. Traditionally, BSD format is over UDP and IETF format is over TCP or SSL/TLS.
      • Facility—Select a syslog standard value (default is LOG_USER) to calculate the priority (PRI) field in your syslog server implementation. Select the value that maps to how you use the PRI field to manage your syslog messages.
   5. (Optional) To customize the format of the syslog messages that the firewall sends, select the Custom Log Format tab. For details on how to create custom formats for the various log types, refer to the Common Event Format Configuration Guide.
   6. Click OK to save the server profile.
2. Configure syslog forwarding for Traffic, Threat, and WildFire Submission logs.
   1. Configure the firewall to forward logs. For more information, see Step Create a Log Forwarding profile.
      1. Select ObjectsLog Forwarding, click Add, and enter a Name to identify the profile.
      2. For each log type and each severity level or WildFire verdict, select the Syslog server profile and click OK.
   2. Assign the log forwarding profile to a security policy to trigger log generation and forwarding. For more information, See Step Assign the Log Forwarding profile to policy rules and network zones.
      1. Select PoliciesSecurity and select a policy rule.
      2. Select the Actions tab and select the Log Forwarding profile you created.
      3. For Traffic logs, select one or both of the Log at Session Start and Log At Session End check boxes, and click OK.

      For detailed information about configuring a log forwarding profile and assigning the profile to a policy rule, see Configure Log Forwarding.
3. Configure syslog forwarding for System, Config, HIP Match, and Correlation logs.
   1. Select DeviceLog Settings.
   2. For System and Correlation logs, click each Severity level, select the Syslog server profile, and click OK.
   3. For Config, HIP Match, and Correlation logs, edit the section, select the Syslog server profile, and click OK.
4. (Optional) Configure the header format of syslog messages.
   The log data includes the unique identifier of the firewall that generated the log. Choosing the header format provides more flexibility in filtering and reporting on the log data for some Security Information and Event Management (SIEM) servers.

   This is a global setting and applies to all Syslog server profiles configured on the firewall.
   1. Select DeviceSetupManagement and edit the Logging and Reporting Settings.
   2. Select the Log Export and Reporting tab and select the Syslog HOSTNAME Format:
      • FQDN (default)—Concatenates the hostname and domain name defined on the sending firewall.
      • hostname—Uses the hostname defined on the sending firewall.
      • ipv4-address—Uses the IPv4 address of the firewall interface used to send logs. By default, this is the MGT interface.
      • ipv6-address—Uses the IPv6 address of the firewall interface used to send logs. By default, this is the MGT interface.
      • none—Leaves the hostname field unconfigured on the firewall. There is no identifier for the firewall that sent the logs.
   3. Click OK to save your changes.
5. Create a certificate to secure syslog communication over TLSv1.2.
   Required only if the syslog server uses client authentication. The syslog server uses the certificate to verify that the firewall is authorized to communicate with the syslog server.

   Ensure the following conditions are met:

   • The private key must be available on the sending firewall; the keys can’t reside on a Hardware Security Module (HSM).
   • The subject and the issuer for the certificate must not be identical.
   • The syslog server and the sending firewall must have certificates that the same trusted certificate authority (CA) signed. Alternatively, you can generate a self-signed certificate on the firewall, export the certificate from the firewall, and import it in to the syslog server.
   • The connection to a Syslog server over TLS is validated using the Online Certificate Status Protocol (OCSP) or using Certificate Revocation Lists (CRL) so long as each certificate in the trust chain specifies one or both of these extensions. However, you cannot bypass OCSP or CRL failures so you must ensure that the certificate chain is valid and that you can verify each certificate using OCSP or CRL.
   1. Select DeviceCertificate ManagementCertificatesDevice Certificates and click Generate.
   2. Enter a Name for the certificate.
   3. In the Common Name field, enter the IP address of the firewall sending logs to the syslog server.
   4. In Signed by, select the trusted CA or the self-signed CA that the syslog server and the sending firewall both trust.
      The certificate can’t be a Certificate Authority nor an External Authority (certificate signing request [CSR]).
   5. Click Generate. The firewall generates the certificate and key pair.
   6. Click the certificate Name to edit it, select the Certificate for Secure Syslog check box, and click OK.
6. Commit your changes and review the logs on the syslog server.
   1. Click Commit.
   2. To review the logs, refer to the documentation of your syslog management software. You can also review the Syslog Field Descriptions.
7. (Optional) Configure the firewall to terminate the connection to the syslog server upon FQDN refresh.
   When you configure a syslog server profile using a FQDN, the firewall maintains its connection to the syslog server by default in the event of an FQDN name change.

   For example, you have replaced an existing syslog server with a new syslog server that uses a different FQDN name. If you want the firewall to connect to the new syslog server using a new FQDN name, you can configure the firewall to automatically terminate its connection to the old syslog server and establish a connection to the new syslog server using the new FQDN name.
   1. Log in to the firewall CLI.
   2. Configure the firewall to terminate the connection to the syslog server upon FQDN refresh.

      admin> set syslogng fqdn-refresh yes