: Forward Logs from Cortex Data Lake to a Syslog Server

Forward Logs from Cortex Data Lake to a Syslog Server

Table of Contents

Forward Logs from
Cortex Data Lake
to a Syslog Server

Learn how to forward logs from
Cortex Data Lake
to a syslog server.
To meet your long-term storage, reporting and monitoring, or legal and compliance needs, you can configure
Cortex Data Lake
to forward all logs or a subset of logs to a syslog receiver.
Cortex Data Lake
can forward logs in multiple formats:
. For each instance of
Cortex Data Lake
, you can forward logs to up to 200 syslog destinations.
Cortex Data Lake
communicates with the receiver using TLS 1.2 and Java 8 default cipher suites (except GCM ciphers, which
Cortex Data Lake
does not currently support). Upon connection,
Cortex Data Lake
validates that the receiver has a certificate signed by a trusted root CA or a private CA. To complete the TLS handshake and establish the connection, the receiver must present all the certificates from the chain of trust.
If you are using the Palo Alto Networks Splunk app, forward logs using HTTPS instead.
  1. (
    QRadar only
    ) Add a log source in QRadar by using the TLS Syslog protocol.
    For details about how to do this, see the IBM documentation.
  2. Enable communication between
    Cortex Data Lake
    and your syslog receiver.
    Ensure that your syslog receiver can connect to
    Cortex Data Lake
    and can present a valid CA certificate to complete the connection request.
    • Allow an inbound TLS feed to your syslog receiver from the IP address range that corresponds to your
      Cortex Data Lake
    • Obtain either a certificate from a well-known, public CA or a self-signed certificate and install it on your receiver. Please make sure that if you are using a certificate signed by a private CA, it contains CRL or OCSP information needed for certificate revocation checks.
      Cortex Data Lake
      validates the server certificate to establish a connection, you must verify that the receiver is configured to properly send the TLS certificate chain to
      Cortex Data Lake
      . If the app cannot verify that the certificate of the receiver and all CAs in the chain are trustworthy, the connection cannot be established. See the list of trusted certificates.
  3. Sign In
    to the hub at https://apps.paloaltonetworks.com/.
  4. Select the
    Cortex Data Lake
    instance that you want to configure for syslog forwarding.
    If you have multiple
    Cortex Data Lake
    instances, click the
    Cortex Data Lake
    tile and select an instance from the list of those available.
  5. Select
    Log Forwarding
    to add a new Syslog forwarding profile.
  6. Enter a descriptive
    for the profile.
  7. Enter the
    Syslog Server
    IPv4 address or FQDN.
    Ensure that the value entered here matches the Subject Alternative Name (SAN) of the certificate installed on your syslog server.
  8. Enter the
    on which the syslog server is listening.
    The default port for syslog messages over TLS is 6514.
  9. Select the
    Choose one of the syslog standard values. The value maps to how your syslog server uses the facility field to manage messages. For details on the facility field, see the IETF standard for the log format (
    CSV, LEEF, or CEF
    ) that you will choose in the next step.
  10. (
    ) Upload a self-signed certificate if you do not want to use a publicly signed certificate.
  11. (
    the private Root CA and intermediate CAs (If an intermediate CA exists). Do not upload the certificate issued for the syslog server—only CA certificates are needed to verify the chain from the syslog server.
    Only do this if you installed a private CA-signed, self-signed certificate on your receiver, or the public CA is not in the list of trusted CAs. The file containing the certificates must be in PEM format.
  12. (
    ) Enable client authentication.
    Do this if company or regulatory policy requires client authentication when forwarding logs to your server.
    1. Download
      the certificate chain.
    2. Upload the certificate chain to your server.
      Refer to the documentation for your server management software to find out how to do this.
  13. Test Connection
    to ensure that
    Cortex Data Lake
    can communicate with the receiver.
    This checks TLS connectivity to verify that transmission is possible.
    If the test fails, you can not proceed.
  14. Click
  15. Specify the
    in which you would like to forward your logs.
    The log format (
    CSV, LEEF, or CEF
    ) that you should select depends on the destination of your log data.
  16. Specify the
    that you would like to separate the fields in your log messages.
  17. (
    ) To receive a
    Cortex Data Lake
    is unable to connect to the syslog server, enter the email address at which you’d like to receive the notification.
    You will continue to receive these notifications every 60 minutes until connectivity is restored. If the connectivity issue is addressed within 72 hours, no logs will be lost. However, any log older than 72 hours following the service disconnection could be lost.
  18. (
    ) Enter a
    to send logs to a cloud syslog receiver.
    If you use a third-party cloud-based syslog service, you can enter a token that
    Cortex Data Lake
    inserts into each syslog message so that the cloud syslog provider can identify the source of the logs.
    1. Follow your cloud syslog provider’s instructions for generating an identifying token.
    2. Enter the
      Profile Token
      Tokens have a maximum length of 128 characters.
  19. Select the logs you want to forward.
    1. Add
      a new log filter.
    2. Select the log type.
      The Threat log type does not include URL logs or Data logs. If you wish to forward these log types, you must add them individually.
    3. (Optional)
      Create a log filter to forward only the logs that are most critical to you.
      You can either write your own queries from scratch or use the query builder. You can also select the query field to choose from among a set of common predefined queries.
      Log filters function like queries in Explore, with the following differences:
      • No double quotes (
      • No subnet masks. To return IP addresses with subnets, use the
        operator. Example:
        src_ip.value LIKE “192.1.1.%”
      If you want to forward all logs of the type you selected, do not enter a query. Instead, proceed to the next step.
    4. Save
      your changes.
  20. Save
    your changes.
  21. Verify that the
    of your Syslog forwarding profile is
    ( ).
  22. Verify that you can view logs on the syslog receiver.
    For details about the log format, refer to the Syslog field descriptions (Select the PAN-OS Administrator’s Guide for your firewall version).
  23. (
    ) You can use the running Syslog forwarding profile to forward past logs spanning up to 3 days.
When configuring event source mapping in your SIEM, be aware that the hostname value can change in the hostname field of the syslog message sent from
Cortex Data Lake
For example,
Oct 8 15:26:51 stream-logfwd20-602226222-10061338-i2hh-harness-r9kt logforwarder LEEF:2.0|Palo Alto Networks|Next Generation
might change to
Oct 8 15:26:51 stream-logfwd20-602226222-10061338-i2hh-harness-
logforwarder LEEF:2.0|Palo Alto Networks|Next Generation
A change to your log forwarding configuration or a new feature/fix could change the hostname value and break event source mapping if you are using an exact match on the hostname.
If hostname exact matching is required by the SIEM, consider using a middle syslog host to rewrite the log forward to a static hostname so that changes to hostname values don't affect log source mappings.

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