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tcp Syslog -- Supported?

  • 1.  tcp Syslog -- Supported?

    Posted 07-12-2012 16:19

    Hi All,


    Is sending syslog from High End SRX (Data plane and Control Plane) supported over TCP instead of UDP.  It would be preferable for ensured delivery of logs.




  • 2.  RE: tcp Syslog -- Supported?

    Posted 07-13-2012 03:20

    I think TCP version of syslog is not supported by JunOS on HE devices. I have used tcp syslog feature supported Cisco ISO using catalyst switches and also used it on ScreenOS.


    syslog config "" transport

    However, a workaround can be a syslong-ng machine (which support tcp syslogging) working as Syslog gateway, transforming UDP Syslog to TCP Syslog; i.e.

    SRX -----<trust>--------- Syslog-ng ------<untrust>------ NMS

    kind regards

  • 3.  RE: tcp Syslog -- Supported?

    Posted 03-18-2019 02:30

    I had the same question. Looks like Junos does not support TCP for system syslog, but supports TCP for security syslog only, see (seems to have some TLS support there as well): set security log transport protocol tcp. For the TCP I tried it, it seems to send the messages in some run-lenght encoded format (you could e.g. do a tcpdump/wireshark capure at the receiving end). It did not work with our use-case (sending the SRX syslogs to fluent-bit, as fluent-bit is not prepared to process this RLE format. I am not a syslog expert and does not have time to read syslog RFC-s, and implement changes to fluent-bit to be able to use the "Junos TCP format" (whether it is standard or not), so I fell back to UDP also for the security syslog for now.

  • 4.  RE: tcp Syslog -- Supported?

    Posted 03-18-2019 03:17



    From your post, I understand that you for got the tcp format working for security syslog but the format is not suitable.


    Can you check if fluent-bit can process the streams in any of these formats?