Although the syslog server has been configured on NFX250, it may not be receiving any messages from JDM.

This article applies to NFX250 running nfx-2 software (Junos versions 18.4 and below).  

Logs are being generated on JDM, but no syslog messages are received on the syslog server.

Syslog messages are being received for vjunos0, but not for JDM.

On Junos OS 15.1X53 code, when committing the syslog configuration, the following error occurs:

error: session failure: unexpected termination
error: remote side unexpectedly closed connection

This problem occurs because external or remote syslog is not supported on JDM.

External or remote syslog logging is not supported on JDM on the NFX250 platform. In fact, set system syslog is a hidden command.

root@jdm# set system ?
Possible completions:
+ apply-groups         Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these groups
> archival             System archival management
> commit
  domain-name          Domain name for this router
+ domain-search        List of domain names to search
  host-name            Hostname for this router
> login                Names, login classes, and passwords for users
> memory               System memory configuration
> name-server          DNS name servers
  password-recovery    Enable system password-recovery mechanism
> root-authentication  Authentication information for the root login
> services             System services
> tacplus-server       TACACS+ server configuration
  time-zone            Time zone name or POSIX-compliant time zone string
{master:0}[edit]
root@jdm# set system

Also, there are no plans to support syslog on JDM. Syslog is supported on NFX250-NG (running the nfx-3 software), wherein everything is configured on vjunos0, which has full support for syslog.

2020-06-03: Added commit errors seen on Junos OS 15.1X53 when configuring syslog
2021-05-11: Added that article applies to NFX250 running nfx-2 software