Configure System Logging

Table 1. Feature History

Feature Name

Release Information

Description

Ability to Send Syslog Messages over TLS

Cisco IOS XE Catalyst SD-WAN Release 17.2.1r

This feature allows you to transport syslog messages to external configured hosts by establishing a Transport Layer Security (TLS) connection. Using the TLS protocol enables the content of syslog messages to remain confidential, secure, and untampered or unaltered during each hop.

Remote Logging Over TCP and TLS in Cisco Catalyst SD-WAN Control Components

Cisco Catalyst SD-WAN Control Components Release 20.13.1

The feature allows remote logging of syslog messages through TCP and TLS. This feature is now available on Cisco Catalyst SD-WAN Control Components (Cisco Catalyst SD-WAN Controller, Cisco Catalyst SD-WAN Validator, and Cisco Catalyst SD-WAN Manager) in addition to Cisco IOS XE Catalyst SD-WAN devices.

System Logging

System logging operations use a mechanism similar to the UNIX syslog command to record system-wide, high-level operations that occur on Cisco Catalyst SD-WAN devices in the overlay network. The log levels (priorities) of the messages are the same as standard UNIX commands, and you can configure the priority of syslog messages. Cisco Catalyst SD-WAN devices can send log messages to a UNIX-style syslog service.

Cisco IOS XE Catalyst SD-WAN devices send syslog messages to syslog servers on configured external hosts using TCP and UDP. When these devices are sending the syslog messages, the messages might transit several hops to reach the output destination. The intermediate networks during the hops might not be trustworthy, be in a different domain, or have a different security level. Therefore, Cisco IOS XE Catalyst SD-WAN devices now support sending secure syslog messages over the Transport Layer Security (TLS) as per RFC5425. To secure the syslog message content from potential tampering, the TLS protocol is used for certificate exchange, mutual authentication, and ciphers negotiation.

Cisco IOS XE Catalyst SD-WAN devices supports both mutual and server authentication for sending syslog messages over TLS.


Note

Disabling system logging to disk (no system logging disk enable) does not disable vsyslog.

Syslog Message Format, Syslog Message Levels, and System Log Files

Syslog Message Format

Syslog messages begin with a percent sign (%) and following are the syslog message formats:

  • Syslog message format

    seq no:timestamp: %facility-severity-MENEMONIC:description (hostname-n)

  • Syslog message format based on RFC5424

    <pri>ver timestamp hostname appname procid msgid structured data description/msg

    Note

    In the syslog message format based on RFC5424, the optional fields such as, hostname, appname, procId, msgId, structured data are specified with a -.

The field descriptions of syslog messages are:

Table 2. Field Descriptions of Syslog Message Format

Field

Description

facility

Sets the logging facility to a value other than 20, which UNIX systems expect.

severity

The importance or severity of the message is categorized by the numerical code from 0 through 7. A lower number in this range indicates greater severity of the system condition.

msg or description

A text string that describes the condition of syslog server. This portion of the syslog message sometimes includes IP addresses, interface names, port numbers, or usernames.

In syslog message formats based on RFC5424, the description represents: %facility-severity-MENEMONIC:description

Usually, the syslog messages are preceded by extra text.

  • The following is an example of a system logging message preceded by a priority value, sequence number, and time stamp:

    <45>10: polaris-user1: *Jun 21 10:76:84.100: %LINK-5-CHANGED: Interface GigabitEthernet0/0, changed state to administratively down

  • Based on RFC5424, the following is an example of a system logging message preceded by a priority value, version of syslog protocol specification, and time stamp:

    <45>1 2003-10-11T22:14:15.003Z 10.64.48.125 polaris-user1 - - - %LINK-5-CHANGED: Interface GigabitEthernet0/0, changed state to administratively down

Note

The time stamp formats are not the same in both the syslog message formats. In the message format based on RFC5424, T, and Z are mandatory where T represents a separator and Z represents zero timezone.

Syslog Message Levels

All syslog messages are associated with priority levels that indicate the severity of syslog messages to save. The default priority value is "informational", so by default, all syslog messages are recorded. The priority level can be one of the following in order of decreasing severity:

  • Emergency—System is unusable (corresponds to syslog severity 0).

  • Alert—Ensure that you act immediately (corresponds to syslog severity 1).

  • Critical—A serious condition (corresponds to syslog severity 2).

  • Error—An error condition that does not fully impair system usability (corresponds to syslog severity 3).

  • Warning—A minor error condition (corresponds to syslog severity 4).

  • Notice—A normal, but significant condition (corresponds to syslog severity 5).

  • Informational—Routine condition (the default) (corresponds to syslog severity 6).

  • Debug—Issues debug messages that correspond to syslog severity 7.

System Log Files

All syslog messages that are at or above the default or configured priority value are recorded in a number of files in the /var/log directory on the local device of the syslog server. The following are the contents of the log files:

  • auth.log—Login, logout, and superuser access events, and usage of authorization systems

  • kern.log—Kernel messages

  • messages.log—Consolidated log file that contains syslog messages from all sources.

  • vconfd.log—All configuration-related syslog messages

  • vdebug.log—All debug messages for modules whose debugging is turned on and all syslog messages that are above the default priority value. The debug log messages support various levels of logging based on the module. The different modules implement the logging levels differently. For example, the system manager (sysmgr) has two logging levels (on and off), while the chassis manager (chmgr) has four different logging levels (off, low, normal, and high). You cannot send debug messages to a remote host. Therefore, to enable debugging, use the debug operational command.

  • vsyslog.log—All syslog messages from Cisco Catalyst SD-WAN processes (daemons) that are above the configured priority value. The default priority value is "informational", so by default, all "notice", "warning", "error", "critical", "alert", and "emergency" syslog messages are saved.

  • vmanage-syslog.log—Cisco SD-WAN Manager NMS Audit log messages

The following are the standard LINUX files that Cisco Catalyst SD-WAN does not use and are available in the /var/log directory.

  • cron.log

  • debug.log

  • lpr.log

  • mail.log

  • syslog

The messages sent to syslog files are not rate-limited and consequently:

  • A storage limit of 10 log files with a capacity of up to 16 MB size is set for each syslog file.

    • When the storage capacity exceeds the 16 MB size limit, the log file is saved as a .GZ file along with the date appended to it.

    • When the storage limit exceeds 10 log files, the oldest log file is dropped.

  • If many syslog messages are generated in a short span of time, the overflowing messages are buffered and queued to be stored in the syslog file.

For repeating syslog messages or identical messages that occur multiple times in succession, only one copy of the message is placed in the syslog file. The message is annotated to indicate the number of times the message occurred.

The maximum length of a log message is 1024 bytes. The longer messages are truncated.

The maximum length of a log message for Cisco SD-WAN Manager NMS audit logs is 1024 bytes. The longer messages are truncated into smaller fragments and each of these fragments are indicated by an identifier. The identifiers are, fragment 1/2, fragment 2/2, and so on. For example, a long audit log message when truncated into smaller fragments appears as:
local6.info: 18-Oct-2020 17:42:07 vm10 maintenance-fragment-1/2: {“logid”: “d9ed576a-43ae-49ce-921b-a51c1ed40698”, “entry_time”: 
1576605512190, “statcycletime” 34542398334245, “logmodule”:”maintenance”, “logfeature”: “upgrade”, “loguser”: “admin”, “logusersrcip”: 
“10.0.1.1”, “logmessage”: “Device validation Upgrade to version — Validation success”, “logdeviceid”:”Validation”, “auditdetails” :
[“[18-Oct-2020 17:42:08 UTC] Published messages to vmanage(s)”, “auditdetails”:[“[18-Oct-2020 17:42:07 UTC] Software image: vmanage-99.99.999-
x86_64.tar.gz”, “Software image download may take up to 60}
local6.info: 18-Oct-2020 17:42:07 vm10 maintenance-fragment-2/2: { minutes”, “logprocessid”: “software_install-7de0ec44-d290-4429-b24532435324”, “tenant”:, “default”}

The syslog messages related to AAA authentication and Netconf CLI access and usage are placed in the auth.log and messages.log files. Each time a Cisco SD-WAN Manager NMS logs into a router to retrieve statistics and status information and to push files to the router, the router generates AAA and Netconf log messages. So, over time, these messages can fill the log files. To prevent these messages from filling the log files, you can disable the logging of AAA and Netconf syslog messages by using the following commands from Cisco SD-WAN Manager NMS:


Note

For information about available syslog messages on Cisco SD-WAN Manager, see Syslog Messages.

Disable logging of AAA and Netconf Syslog Messages

  1. vManage# config

    Enters the configuration mode terminal

  2. vManage(config)# system aaa logs

    Configures the logging of AAA and Netconf system logging (syslog) messages

  3. vManage(config-logs)# audit-disable

    Disable logging of AAA events

  4. vManage(config-logs)# netconf-disable

    Disable logging of Netconf events

  5. vManage(config-logs)# commit

    Commit complete.

Benefits of Using TLS for Sending Syslog Messages

The benefits of using TLS for sending syslog messages are:

  • Confidentiality of message content where each TLS session begins with a handshake between the Cisco IOS XE Catalyst SD-WAN device and the syslog server. The Cisco IOS XE Catalyst SD-WAN device and syslog server agree on the specific security key and the encryption algorithms to be used for that session. The TLS session opposes any disclosure of the contents of the syslog message.

  • Integrity-checking of the content of each message to disable modifications to a message during transit on a hop-by-hop basis.

  • Mutual authentication between the Cisco IOS XE Catalyst SD-WAN device and syslog server ensures that the syslog server accepts log messages only from authorized clients through certificate exchange.

Configure Logging in Server Authentication for TLS

In server authentication, Cisco IOS XE Catalyst SD-WAN devices verify the identity of the syslog server. If the syslog server and the certificate are legitimate entities, the device establishes a TLS connection with the server. For implementing server authentication, the syslog server shares the public certificate with the Cisco IOS XE Catalyst SD-WAN devices.

Prerequisite

Ensure that Cisco IOS XE Catalyst SD-WAN devices have preinstalled Root Certificate Authority (CA), which you configure using cryptographic module CLIs. See Install root CA on Cisco IOS XE Catalyst SD-WAN device.

To configure TLS profile for syslog server, perform the following steps:

  1. Configure logging feature template using Cisco vManage.

    1. Configure logging attributes to local disk.

    2. Configure syslog server for TLS.

  2. Create a device template from logging feature template.

Configure Logging in Mutual Authentication for TLS

In mutual authentication, both the syslog server and Cisco IOS XE Catalyst SD-WAN device authenticate each other at the same time. Cisco IOS XE Catalyst SD-WAN devices must have root or identity certificates for mutual authentication of the TLS session. To configure TLS profile for syslog server, perform the following steps:

  1. Install Syslog Root Certificate on Cisco IOS XE Catalyst SD-WAN device.

  2. Configure logging feature template using Cisco vManage.

    1. Configure logging attributes to local disk.

    2. Generate Feature Certificate Signing Request and Install Feature Certificates

    3. Configure syslog server for TLS.

  3. Create a device template from logging feature template.

  4. Generate Feature Certificate Signing Request and Install Feature Certificates.

  5. Verify trustpoint configuration on Cisco IOS XE Catalyst SD-WAN device.

Install Root Certificate Authority on Cisco IOS XE Catalyst SD-WAN Device for Server Authentication

Before you begin

Ensure that you generate the encoded CA certificate on the syslog server. See Install Root Certificate Authority on Syslog Server for Server Authentication.

Procedure

Step 1

To configure PKI trustpoint for Certificate Authority, use these commands for authorizing and revocation of certificates in PKI.

  1. enable

    Enables privileged EXEC mode.

    Example:

    Cisco XE SD-WAN> enable

  2. config-transaction

    Enters the configuration mode.

    Example:

    Cisco XE SD-WAN# config-transaction

  3. crypto pki trustpoint name

    Declares the trustpoint and a given name and enters CA-trustpoint configuration mode.

    Example:

    Cisco XE SD-WAN (config)# crypto pki trustpoint Syslog-signing-CA

  4. enrollment [mode] [retry period minutes ] [retry count number ] url url [pem ]

    Specifies the enrollment parameters of the CA.

    Example:

    Cisco XE SD-WAN(ca-trustpoint)# enrollment terminal

  5. chain-validation [{stop | continue}[parent-trustpoint]]

    Configures the level to which a certificate chain is processed on all certificates.

    Example:

    Cisco XE SD-WAN(ca-trustpoint)# chain-validation stop

  6. revocation-check method

    (Optional) Checks the revocation status of a certificate.

    Example:

    Cisco XE SD-WAN(ca-trustpoint)# revocation-check none

  7. exit

    Returns to global configuration mode.

    Example:

    Cisco XE SD-WAN(ca-trustpoint)# exit

Step 2

Retrieve and authenticate the Root CA before the Cisco IOS XE Catalyst SD-WAN device can be issued a certificate and certificate enrollment occurs.

To authenticate the CA, use the crypto pki authenticate command.

Example:

Cisco XE SD-WAN(config)# crypto pki authenticate root

Step 3

Copy the block of text containing the base 64 encoded CA certificate and paste it at the prompt.

To generate and copy the text containing the encoded CA certificate, see Install Root Certificate Authority on Syslog Server for Server Authentication.

Example:

A sample base 64 encoded CA certificate:

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Step 4

Type yes to confirm the acceptance of the certificate.

The Root CA certificate is successfully imported.

What to do next

Configure Logging Feature Template Using Cisco SD-WAN Manager

Install Root Certificate Authority on Syslog Server for Server Authentication

In this document, the following steps describe the procedure to set up syslog-ng server that supports TLS.

Procedure

Step 1

To install syslog-ng on the server, use the following command:

Example:

# apt-get install syslog-ng openssl

Step 2

To change the directory to syslog-ng folder and create folders to store the root certificates, use the following commands:

Example:

# cd /etc/syslog-ng
# mkdir cert.d
# mkdir key.d
# mkdir ca.d
# cd cert.d
# openssl req -new -x509 -out cacert.pem -days 1095 -nodes
# mv privkey.pem ../key.d
After using the openssl command, an encoded root certificate is available in cacert.pem file. The file is located in the cd/etc/syslog-ng/cert.d directory.

Step 3

Copy the content from the cacert.pem file when installing root certificate on Cisco IOS XE Catalyst SD-WAN Device. See Step 3 of Install Root Certificate Authority on Cisco IOS XE Catalyst SD-WAN Device for Server Authentication.

What to do next

Install Root Certificate Authority on Cisco IOS XE Catalyst SD-WAN Device for Server Authentication

Install Syslog Root Certificate on Cisco IOS XE Catalyst SD-WAN Device for Mutual Authentication

To configure Cisco IOS XE Catalyst SD-WAN devices with Transport Layer Security (TLS) syslog protocol, the devices must have root or identity certificates for mutual authentication of TLS session. You can either use a third-party Certificate Authority (CA) to get public key infrastructure (PKI) services, or Microsoft Active Directory Certificate Services (AD CS). AD CS allows you to build a PKI and provide public key cryptography, digital certificates, and digital signature capabilities for your requirement.

Procedure

Step 1

Generate the enterprise root certificate using a third party CA or Microsoft Active Directory Certificate Services.

Step 2

Download the root CA in base 64 format, select and copy the content of root CA.

Step 3

From the Cisco SD-WAN Manager menu, choose Administration > Settings.

Step 4

Click Enterprise Feature Certificate Authorization.

Step 5

Paste the root CA content in the Enterprise Root Certificate box.

Step 6

(Optional) if you want to generate a Certificate Signing Request (CSR), check the Set CSR Properties check box.

Step 7

Click Close.

The root CA is uploaded to Cisco SD-WAN Manager, and Cisco SD-WAN Manager saves the root certificate to the Cisco IOS XE Catalyst SD-WAN device.

What to do next

Configure Logging Feature Template Using Cisco SD-WAN Manager

Configure Logging Feature Template Using Cisco SD-WAN Manager

On Cisco IOS XE Catalyst SD-WAN device , you can log event notification system log (syslog) messages to files on the local device, or you can log them to files on a remote host using Cisco SD-WAN Manager.

Procedure

Step 1

From the Cisco SD-WAN Manager menu, choose Configuration > Templates.

Step 2

Click Feature Templates, and click Add Template.

Note

 

In Cisco vManage Release 20.7.x and earlier releases, Feature Templates is titled Feature.

Step 3

From Select Devices, choose the device for which you wish to create a template.

Step 4

To create a template for logging, select Cisco Logging.

The Cisco Logging template form appears. This form contains fields for naming the template, and fields for defining the Logging parameters. Click a tab or the plus sign (+) to display other fields.

When you first open a feature template, the scope is set to Default for those parameters that have a default value. The default setting or value appears next to a parameter. To change the default or to enter a value, click the Scope drop-down list to the left of the parameter field.

Step 5

In Template Name, enter a name for the template.

The name may contain up to 128 alphanumeric characters.

Step 6

In Template Description, enter a description of the template.

The description may contain up to 2048 alphanumeric characters.

What to do next

Configure Logging Attributes to Local Disk

Configure Logging Attributes to Local Disk

  1. Click Disk and configure the following parameters:

    Table 3. Parameter Information

    Parameter

    Description

    Enable Disk

    To save syslog messages in a file on the local hard disk, click On or Off to disallow saving. By default, logging to a local disk file is enabled on all devices.

    Maximum File Size

    Enter the maximum size of syslog files. The syslog files are rotated on an hourly basis based on the file size. When the file size exceeds configured value, the file is rotated and the syslogd process is notified.

    Range: 1-20 MB

    Default: 10 MB

    Rotations

    Enter the number of syslog files to create before discarding the earliest created files.

    Range: 1-10 MB

    Default: 10 MB

  2. To save the feature template, click Save.

  3. To associate the feature template with a device template, see Create a Device Template from Feature Templates.

What to Do Next

Configure TLS Profile for Server Authentication or Configure TLS Profile for Mutual Authentication

Configure TLS Profile for Server Authentication

  1. Click TLS Profile.

  2. Click New Profile, and configure the following parameters:

    Table 4. Parameter Information

    Parameter Name

    Description

    Profile Name

    Enter the TLS profile name

    TLS Version

    Choose TLS versions v1.1 or v1.2

    Authentication Type

    Choose authentication types as Server.

    Ciphersuites

    Choose groups of cipher suites (encryption algorithm) based on the TLS version.

    The following are the list of cipher suites.

    • aes-128-cbc-sha Encryption type tls_rsa_with_aes_cbc_128_sha

    • aes-256-cbc-sha Encryption type tls_rsa_with_aes_cbc_256_sha

    • dhe-aes-128-cbc-sha Encryption type tls_dhe_rsa_with_aes_128_cbc_sha

    • dhe-aes-cbc-sha2 Encryption typetls_dhe_rsa_with_aes_cbc_sha2(TLS1.2 & above)

    • dhe-aes-gcm-sha2 Encryption typetls_dhe_rsa_with_aes_gcm_sha2(TLS1.2 & above)

    • ecdhe-ecdsa-aes-gcm-sha2 Encryption type tls_ecdhe_ecdsa_aes_gcm_sha2(TLS1.2 & above) SuiteB

    • ecdhe-rsa-aes-128-cbc-sha Encryption type tls_ecdhe_rsa_with_aes_128_cbc_sha

    • ecdhe-rsa-aes-cbc-sha2 Encryption type tls_ecdhe_rsa_aes_cbc_sha2(TLS1.2& above)

    • ecdhe-rsa-aes-gcm-sha2 Encryption type tls_ecdhe_rsa_aes_gcm_sha2(TLS1.2& above)

    • rsa-aes-cbc-sha2 Encryption type tls_rsa_with_aes_cbc_sha2(TLS1.2 & above)

    • rsa-aes-gcm-sha2 Encryption type tls_rsa_with_aes_gcm_sha2(TLS1.2 & above)

    You can use the following cipher suites for each TLS version:
    TLS v1.1
    aes-128-cbc-sha Encryption type tls_rsa_with_aes_cbc_128_sha
aes-256-cbc-sha Encryption type tls_rsa_with_aes_cbc_256_sha
    TLS v1.2 and later
    dhe-aes-cbc-sha2 Encryption type tls_dhe_rsa_with_aes_cbc_sha2(TLS1.2 & above)
dhe-aes-gcm-sha2 Encryption type tls_dhe_rsa_with_aes_gcm_sha2(TLS1.2 & above)

ecdhe-ecdsa-aes-gcm-sha2 Encryption type tls_ecdhe_ecdsa_aes_gcm_sha2 (TLS1.2 & above)
ecdhe-rsa-aes-cbc-sha2 Encryption type tls_ecdhe_rsa_aes_cbc_sha2(TLS1.2 & above)
ecdhe-rsa-aes-gcm-sha2 Encryption type tls_ecdhe_rsa_aes_gcm_sha2(TLS1.2 & above)
 
rsa-aes-cbc-sha2 Encryption type tls_rsa_with_aes_cbc_sha2(TLS1.2 & above) 
rsa-aes-gcm-sha2 Encryption type tls_rsa_with_aes_gcm_sha2(TLS1.2 & above)

    The TLS profiles appear in a table.

  3. To create another profile, click Add.

  4. To edit or delete a TLS profile information, click or under Action.

  5. To save the feature template, click Save.

  6. To associate the feature template with a device template, see Create a Device Template from Feature Templates.

When you choose the authentication type as Server, all information about TLS profiles, except the trustpoint information, is saved.

What to Do Next

Configure Logging to Remote Severs

Configure TLS Profile for Mutual Authentication

  1. Click TLS Profile.

  2. Click New Profile, and configure the following parameters:

    Table 5. Parameter Information

    Parameter Name

    Description

    Profile Name

    Enter the TLS profile name

    TLS Version

    Choose TLS versions v1.1 or v1.2

    Authentication Type

    Choose authentication types as Mutual.

    Ciphersuites

    Choose groups of cipher suites (encryption algorithm) based on the TLS version that must be used for encryption.

    The following are the list of cipher suites.

    • aes-128-cbc-sha Encryption type tls_rsa_with_aes_cbc_128_sha

    • aes-256-cbc-sha Encryption type tls_rsa_with_aes_cbc_256_sha

    • dhe-aes-128-cbc-sha Encryption type tls_dhe_rsa_with_aes_128_cbc_sha

    • dhe-aes-cbc-sha2 Encryption typetls_dhe_rsa_with_aes_cbc_sha2(TLS1.2 & above)

    • dhe-aes-gcm-sha2 Encryption typetls_dhe_rsa_with_aes_gcm_sha2(TLS1.2 & above)

    • ecdhe-ecdsa-aes-gcm-sha2 Encryption type tls_ecdhe_ecdsa_aes_gcm_sha2(TLS1.2 & above) SuiteB

    • ecdhe-rsa-aes-128-cbc-sha Encryption type tls_ecdhe_rsa_with_aes_128_cbc_sha

    • ecdhe-rsa-aes-cbc-sha2 Encryption type tls_ecdhe_rsa_aes_cbc_sha2(TLS1.2& above)

    • ecdhe-rsa-aes-gcm-sha2 Encryption type tls_ecdhe_rsa_aes_gcm_sha2(TLS1.2& above)

    • rsa-aes-cbc-sha2 Encryption type tls_rsa_with_aes_cbc_sha2(TLS1.2 & above)

    • rsa-aes-gcm-sha2 Encryption type tls_rsa_with_aes_gcm_sha2(TLS1.2 & above)
    You can use the following cipher suites for each TLS version:
    TLS v1.1
    aes-128-cbc-sha Encryption type tls_rsa_with_aes_cbc_128_sha
aes-256-cbc-sha Encryption type tls_rsa_with_aes_cbc_256_sha
    TLS v1.2 and later
    dhe-aes-cbc-sha2 Encryption type tls_dhe_rsa_with_aes_cbc_sha2(TLS1.2 & above)
dhe-aes-gcm-sha2 Encryption type tls_dhe_rsa_with_aes_gcm_sha2(TLS1.2 & above)

ecdhe-ecdsa-aes-gcm-sha2 Encryption type tls_ecdhe_ecdsa_aes_gcm_sha2 (TLS1.2 & above)
ecdhe-rsa-aes-cbc-sha2 Encryption type tls_ecdhe_rsa_aes_cbc_sha2(TLS1.2 & above)
ecdhe-rsa-aes-gcm-sha2 Encryption type tls_ecdhe_rsa_aes_gcm_sha2(TLS1.2 & above)
 
rsa-aes-cbc-sha2 Encryption type tls_rsa_with_aes_cbc_sha2(TLS1.2 & above) 
rsa-aes-gcm-sha2 Encryption type tls_rsa_with_aes_gcm_sha2(TLS1.2 & above)

    The TLS profiles appear in a table.

  3. To create another profile, click Add.

  4. To edit or delete a TLS profile information, click or under Action.

  5. To save the feature template, click Save.

  6. Associate the feature template with a device template. See Create a Device Template from Feature Templates.

The mutually authenticated feature template is saved on the Cisco IOS XE Catalyst SD-WAN devices, and trustpoint such as, SYSLOG-SIGNING-CA certificate is saved on the device. Cisco SD-WAN Manager can now install the certificate from Cisco IOS XE Catalyst SD-WAN devices.

What to Do Next

Configure Logging to Remote Severs

Configure Logging to Remote Severs

To include the TLS profile in IPV6 or IPV4 server configuration and configure logging of event notification system log messages to a remote server,

  1. Click Server.

  2. Click Add New Server, and configure the following parameters for IPv4 or IPv6:

    Table 6. Parameter Information

    Parameter Name

    Description

    Hostname/IP Address

    Enter the DNS name, hostname, or IPv4, IPv6 address of the system on which to store syslog messages.

    To add another syslog server, click +.

    To delete a syslog server, click .

    VPN ID

    Enter the identifier of the VPN in which the syslog server is located or through which the syslog server can be reached.

    VPN ID Range: 0-65530

    Source Interface

    Enter the specific interface to use for outgoing system log messages. The interface must be located in the same VPN as the syslog server. Otherwise, the configuration of syslog servers is ignored. If you configure multiple syslog servers, the source interface must be same for all of them.

    Priority

    Choose a severity of the syslog message to be saved. The severity indicates the seriousness of the event that generated the syslog message. See priority levels.

    TLS

    For Cisco IOS XE Catalyst SD-WAN devices, click On to enable syslog over TLS.

    Custom Profile

    For Cisco IOS XE Catalyst SD-WAN devices, click On to enable choosing a TLS profile, or click Off to disable choosing a TLS profile.

    TLS Profile

    For Cisco IOS XE Catalyst SD-WAN devices, choose a TLS profile that you have created for server or mutual authentication in IPv4 or IPv6 server configuration.

    The server entries appear in a table.

  3. To create another entry for a server, click Add.

  4. To edit a logging server, click .

  5. To remove a logging server, click .

  6. To save the feature template, click Save.

  7. To associate the feature template with a device template, see Create a Device Template from Feature Templates.

Generate Feature Certificate Signing Request and Install Feature Certificates

To validate and authenticate Cisco IOS XE Catalyst SD-WAN devices and syslog server, perform the following operation on the Cisco SD-WAN Manager Certificates screen. See Cisco Catalyst SD-WAN Getting Started Guide for information about enterprise certificates.

Procedure

Step 1

From the Cisco SD-WAN Manager menu, choose Configuration > Certificates.

Step 2

From Certificates, choose a Cisco IOS XE Catalyst SD-WAN device.

  1. Generate Feature Certificate Signing Request (CSR).

    After you generate the Feature CSR, the View Feature CSR and Install Feature certificate options are available. ​

  2. View Feature CSR.

  3. To download the feature CSR, click Download.

Step 3

To sign the certificate, send the certificate to a third-party signing authority.

Step 4

To import the certificate into Cisco IOS XE Catalyst SD-WAN devices, Install feature certificate.

The Install Feature Certificate screen uses the signed certificate and installs it on Cisco IOS XE Catalyst SD-WAN devices.

After the feature certificate installation is successful, the Revoke Feature Certificate and View Feature Certificate options are available on Cisco SD-WAN Manager.

What to do next

Verify Trustpoint Configuration on Cisco IOS XE Catalyst SD-WAN Device

Verify Trustpoint Configuration on Cisco IOS XE Catalyst SD-WAN Device

To display the contents of syslog file with trustpoint information for Cisco IOS XE Catalyst SD-WAN device, use the show crypto pki trustpoints status command.

Examples

Server authentication

Cisco XE SD-WAN# show crypto pki trustpoints status
 
crypto pki trustpoint SYSLOG-SIGNING-CA
  enrollment url bootflash:vmanage-admin/
  fqdn none
  fingerprint xxxxxx
  revocation-check none
  subject-name CN=CSR-cbc47d9d-45bf-433a-9816-1f12a8b48223_vManage Root CA

Mutual authentication

Cisco XE SD-WAN# show crypto pki trustpoints status
 
crypto pki trustpoint SYSLOG-SIGNING-CA
  enrollment url bootflash:vmanage-admin/
  fqdn none
  fingerprint xxxxxx
  revocation-check none
  rsakeypair SYSLOG-SIGNING-CA 2048
  subject-name CN=CSR-cbc47d9d-45bf-433a-9816-1f12a8b48223_vManage Root CA

Verify trustpoints on a device for a Syslog-signing-CA certificate

Cisco XE SD-WAN# show crypto pki trustpoints SYSLOG-SIGNING-CA status
 
Trustpoint SYSLOG-SIGNING-CA:                                                                                                   
 Issuing CA certificate not configured.                                                                                        
State:                                                                                                                        
Keys generated ............. No                                                                                             
 Issuing CA authenticated ....... No                                                                                         
  Certificate request(s) ..... None

Export Cisco SD-WAN Manager NMS Audit Log to Syslog Server

Table 7. Feature History

Feature Name

Release Information

Description

Export Cisco SD-WAN Manager Audit Log as Syslog

Cisco IOS XE Catalyst SD-WAN Release 17.3.1a

Cisco vManage Release 20.3.1

The Cisco SD-WAN Manager exports audit logs in syslog message format to a configured external syslog server. This feature allows you to consolidate and store network activity logs in a central location.

On Cisco IOS XE Catalyst SD-WAN devices and Cisco vEdge devices, you can log event notification system log (syslog) messages to files on a local device, or to files on a remote host using CLI. These event notification logs are converted to system log files and exported to the syslog server. You can then retrieve system log information from the syslog server.

Configure System Logging Using CLI

Log Syslog Messages to a Local Device

By default, a priority level of “information” is enabled when you log syslog messages to a file on a local device. Use the following commands:

  1. logging disk

    Logs syslog messages on a hard disk

    Example:

    vm01(config-system)# logging disk

  2. enable

    Enables logging to a disk

    Example:

    vm01(config-logging-disk)# enable

  3. file size size

    Specifies the size of syslog files in megabytes (MB) By default, the syslog files are 10 MB. You can configure the size of syslog files to be 1–20 MB.

    Example:

    vm01(config-logging-disk)# file size 3

  4. file rotate number

    Rotates syslog files on an hourly basis based on the size of the file By default, 10 syslog files are created. You can configure the rotate command to be a number from 1 through 10.

    Example:

    vm01(config-logging-disk)# file rotate 3

For more information about logging disk commands, see the logging disk command.

Log Syslog Messages to a Remote Device

To log event notification system log (syslog) messages to a remote host, use the following commands:

  1. logging server

    Logs syslog messages to a remote host or syslog server You can configure the name of the server by DNS name, hostname, or IP address. You can configure up to four syslog servers.

    Example:

    vm01(config-system)# logging server 192.168.0.1

  2. (Optional) vpn vpn-id

    Specifies the VPN ID of the syslog server

  3. (Optional) source interface interface-name

    Specifies the source interface to reach the syslog server. The interface name can be a physical interface or a sub-interface (a VLAN-tagged interface). Ensure that the interface is located in the same VPN as the syslog server. Otherwise, the configuration is ignored. If you configure multiple syslog servers, the source interface must be the same for all of them.

    Example:

    vm01(config-server-192.168.0.1)# source interface eth0

  4. priority priority

    Specifies the severity of the syslog message to be saved. The default priority value is "informational" and by default, all syslog messages are recorded.

    Example:

    In the following example, set the syslog priority to log alert conditions.

    vm01(config-server-192.168.0.1)# priority alert

If the syslog server is unreachable, the system suspends sending syslog messages for 180 seconds. When the server becomes reachable, logging resumes. For more information about logging server commands, see the logging server command.

View System Logging Information

To view system log settings after logging syslog messages to a remote host, use the show logging command. For example: 

vm01(config-server-192.168.0.1)# show logging

System logging
    server 192.168.0.1
    source interface eth0
    exit
!
!

To view the contents of the syslog file, use the show log command. For example: 

vm01(config-server-192.168.0.1)# show log nms/vmanage-syslog.log tail 10

To view the configured system logging settings from Cisco SD-WAN Manager, see Audit Log.

To view device-specific syslog files from Cisco SD-WAN Manager, perform the following steps:

  1. From the Cisco SD-WAN Manager menu, choose Administration > Settings, and ensure that you enable Data Stream.

  2. From the Cisco SD-WAN Manager menu, choose Monitor > Devices, and choose a Cisco IOS XE Catalyst SD-WAN device

    Cisco vManage Release 20.6.x and earlier: From the Cisco SD-WAN Manager menu, choose Monitor > Network, and choose a Cisco IOS XE Catalyst SD-WAN device.

  3. Click Troubleshooting.

  4. From Logs, click Debug Log.

  5. From Log Files, select a name of the log file to view the log information.

Remote Logging Over TCP and TLS in Cisco Catalyst SD- WAN Control Components

Information About Remote Logging Over TCP and TLS

Starting from Cisco IOS XE Catalyst SD-WAN Release 17.13.1a and Cisco Catalyst SD-WAN Manager Release 20.13.1, support for remote logging of syslog messages has been enhanced to include TCP and TLS transport methods in addition to UDP. This enhancement applies to Cisco Catalyst SD-WAN Control Components including Cisco Catalyst SD-WAN Controller, Cisco Catalyst SD-WAN Validator, and Cisco Catalyst SD-WAN Manager.

By default, UDP is enabled as the default transport type for remote logging. However, users now have the additional option to select either TCP or TLS as their transport method for remote logging.

For more information, see System Logging

Benefits of Remote Logging Over TCP and TLS

  • Syslog over TCP and TLS supports large-scale network environments. While TCP can handle large volumes of data, TLS can ensure that the log data is securely sent and protected from unauthorized access or tampering.

  • You can configure up to four separate remote syslog servers with the option to assign each server a unique transport protocol such as UDP, TLS, or TCP. Alternatively, you can choose to use the same transport protocol for all four servers.

  • For remote logging over TLS, a TLS profile supports TLS version 1.2. Also, various cipher suites can be accommodated within the TLS profile, depending on the TLS version.

Configure Remote Logging Over TCP and TLS

  1. From the Cisco SD-WAN Manager menu, choose Configuration > Templates.

  2. Click Feature Templates.

  3. Click Add Template to select an appropriate device model.

  4. In the left pane, from Select Devices, choose a a Cisco Catalyst SD-WAN control component.

  5. Under OTHER TEMPLATES, click Logging to select it as the feature template.

  6. In the Template Name field, enter a name for the feature template.

    This field is mandatory and can contain only uppercase and lowercase letters, the digits 0 to 9, hyphens (-), and underscores (_). It cannot contain spaces or any other characters.

  7. In the Description field, enter a description for the feature template.

    This field is mandatory, and it can contain all characters and spaces.

  8. Configure Logging Attributes to Local Disk.

    1. Click Disk and configure the following parameters:

      Table 8. Parameter Information

      Parameter

      Description

      Enable Disk

      To save syslog messages in a file on the local hard disk, click On or Off to disallow saving. By default, logging to a local disk file is enabled on all devices.

      Maximum File Size

      Enter the maximum size of syslog files. The syslog files are rotated on an hourly basis based on the file size. When the file size exceeds the configured value, the file is rotated and the syslogd process is notified.

      Range: 1 to 20 MB

      Default: 10 MB

      Rotations

      Enter the number of syslog files to create before discarding the earliest created files.

      Range: 1 to 10 MB

      Default: 10 MB

    2. To save the feature template, click Save.

    3. To associate the feature template with a device template, see Create a Device Template from Feature Templates.

Configure TLS Profile for Server Authentication

  1. From the TLS Profile section, click New Profile to configure a TLS profile.

    Table 9. TLS Profile Parameters

    Parameter Name

    Description

    Profile Name

    Enter the TLS profile name

    TLS Version

    Choose TLS v1.2.

    Ciphersuites

    Choose one or more ciphersuites based on the TLS version.

    The following ciphersuites are supported:

    • ECDHE-ECDSA-AES256-GCM-SHA384

    • ECDHE-RSA-AES256-GCM-SHA384

    • DHE-RSA-AES256-GCM-SHA384

    • ECDHE-ECDSA-AES128-GCM-SHA256

    • ECDHE-RSA-AES128-GCM-SHA256

    • DHE-RSA-AES128-GCM-SHA256

    • ECDHE-ECDSA-AES256-SHA384

    • ECDHE-RSA-AES256-SHA384

    • DHE-RSA-AES256-SHA256

    • ECDHE-ECDSA-AES128-SHA256

    • ECDHE-RSA-AES128-SHA256

    • DHE-RSA-AES128-SHA256

    • RSA-PSK-AES256-GCM-SHA384

    • DHE-PSK-AES256-GCM-SHA384

    • AES256-GCM-SHA384

    • PSK-AES256-GCM-SHA384

    • RSA-PSK-AES128-GCM-SHA256

    • DHE-PSK-AES128-GCM-SHA256

    • AES128-GCM-SHA256

    • PSK-AES128-GCM-SHA256

    • AES256-SHA256

    • AES128-SHA256

  2. (Optional) Click Add to create another profile.

Configure Syslog Servers for TLS/TCP/UDP

  1. From the Server section, click New Server to configure syslog servers.

    Table 10. Syslog Servers Parameters

    Parameter Name

    Description

    Hostname/IP Address

    Enter the DNS name, hostname, IPv4 or IPv6 address of the server on which to store syslog messages.

    To add another syslog server and its details, click Add.

    VPN ID

    Enter the identifier of the VPN in which the syslog server is located or through which the syslog server can be reached.

    Range is 0 to 65530

    Source Interface

    Enter the specific interface to use for outgoing system log messages.

    Priority

    Choose a logging level for syslog messages that you want to log on the server. The logging level indicates the type of event that generated the syslog message. See priority levels.

    Transport for messages logged to remote host

    Choose either TCP, UDP, or TLS as the transport type for forwarding syslog messages to a remote server.

    Port for transport (default 514)

    Specify the port number for the transport type.

    TLS Profile

    This field displays if you have chosen the transport type as TLS. Choose a TLS profile to attach a TLS profile. See Configure TLS Profile for Server Authentication

  2. (Optional) Click Add to create another entry for a server.

  3. Click Save to save the feature template

Apply the Logging Feature Template to a Device

  1. From the Cisco SD-WAN Manager menu, choose Configuration > Templates.

  2. Click Device Templates.

  3. From the Create Template drop-down list, choose From Feature Template

  4. From the Device Model drop-down list, choose one of the devices.

  5. In the Template Name field, enter a name for the feature template.

    This field is mandatory and can contain only uppercase and lowercase letters, the digits 0 to 9, hyphens (-), and underscores (_). It cannot contain spaces or any other characters.

  6. In the Description field, enter a description for the device template.

    This field is mandatory, and it can contain all characters and spaces.

  7. From the Cisco Logging drop-down list, choose the template that you created for remote logging.

  8. Click Create to apply the template to a device.

  9. From the list of device templates, click … next to the device template that you created.

  10. Click Attach Devices.

  11. Choose the devices to which you want to attach the device template.

  12. Click Attach to the template to the devices.

Configure Remote Logging Over TCP and TLS

For more information about using CLI templates, see CLI Add-On Feature Templates and CLI Templates.


Note

By default, CLI templates execute commands in global config mode.

This section provides sample CLI configurations to configure a remote server for logging with transport type as TCP and TLS.

Configure Remote Server with Transport Type as TCP

Configure Remote Server with Transport Type as TCP.

system 
 logging 
  server <server-ip-address> 
  transport tcp port 514

Configure Remote Server with Transport Type as TLS

Configuring a remote server for logging with Transport type as TLS is a three-step process.

  1. Manage Certificate

    To manage the Certificate Authority (CA) certificate from the syslog server, use the following commands below to install, list, and uninstall the certificates.

    • Install a Certificate

      A certificate can be installed from either a local directory, such as /home/admin, or remotely using secure copy (scp), HTTP, or FTP. 

      
request logging ca-cert  
 install new syslog-ng ca

    • List All Installed Certificates

      show logging cacert

    • Uninstall a Certificate

      request logging ca-cert uninstall <cert-name>

  2. Create a TLS Profile

    Creating a TLS profile involves specifying the protocols and cipher suites that a device will use for secure communication. You can configure up to four TLS profiles.

    Use the following configuration to create a TLS profile:

    system  
 logging  
 tls-profile <profile-name> 
  tls-version TLSv1.2  
  ciphersuite <ciphersuite1> <ciphersuite2>

  3. Attach a TLS Profile to a Remote Logging Server

    Use the following configuration to attach a TLS profile to the remote logging servers:

    server<server-ip-address>  
 vpn <vpn-instance-of-logging-server> 
 source-interface <interface-num> 
 transport tls
 tls-profile <tls-profile-name>

Verify Remote Logging Over TCP and TLS

The following is a sample output from the show logging cacert command to view installed certificates.
Device# show logging cacert 
INDEX  NAME      VALIDITY
--------------------------------------------
0      cert.pem  Fri Jun 21 20:35:10 2024

Configuration Example for Support for Syslog over TCP and TLS

Configuration Example for Logging Over TLS

This example shows the configuration for logging over TLS.

system
logging
  disk
   enable
  !
  tls-profile profile1
   version     TLSv1.2
   ciphersuite ECDHE-ECDSA-AES128-SHA256 AES256-GCM-SHA384 PSK-AES256-GCM-SHA384 PSK-AES128-GCM-SHA256 AES256-SHA256
  exit
  server 10.0.1.55
   source interface 10.1.1.12
   transport   tls
   tls-profile profile1
  exit
!
!

Configuration Example for Logging Over TCP

This example shows the configuration for logging over TCP.

system
logging
  disk
   enable
  !
  server 10.0.1.56
   transport tcp
  exit
!
!