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N__197982's avatar
N__197982
Icon for Nimbostratus rankNimbostratus
Jan 11, 2019

iRule to log an output to syslog server.

Folks, I am looking for some changes to an iRule while will log an output to a syslog server directly. My iRule check if the connection is on TLS1.0 and if yes logs the client IP address.

 

The change I need is to log this client IP to a syslog server.

 

Here is the iRule: when HTTP_REQUEST { if { [SSL::cipher version] eq "TLSv1" } { log local0. "Webmail Client Source IP: [IP::client_addr]" } }

 

Thanks!!!! N.

 

application delivery
iRules

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  • PeteWhite's avatar
    PeteWhite
    Icon for Employee rankEmployee
    Jan 11, 2019

    You want to use HSL - high-speed logging. You can do that either to a pool ( of log servers ) or via a publisher. Below is an example to a pool but i'm sure you can work out how to send it to a publisher.

    when HTTP_REQUEST { 
    if { [SSL::cipher version] eq "TLSv1" } { 
        set hsl [HSL::open -proto UDP -pool syslog_server_pool]
        HSL::send $hsl "Webmail Client Source IP: [IP::client_addr]" 
    } 
}

    Take a look here for details of the HSL commands

  • Kai_Wilke's avatar
    Kai_Wilke
    Icon for MVP rankMVP
    Jan 11, 2019

    Hi N.,

    you may take a look to the 

    [HSL]
    (High Speed Logging) iRule command. The command will bypass the local SYSLOG-NG environment and directly open a connection to your SYSLOG out of an iRule...

    https://devcentral.f5.com/wiki/iRules.HSL.ashx

    when CLIENT_ACCEPTED {
     Open a UDP based SYSLOG connection to your syslog server pool.
    set hsl [HSL::open -proto UDP -pool syslog_server_pool]
}
when HTTP_REQUEST { 
    if { [SSL::cipher version] eq "TLSv1" } then {
         Log client IP as local7.info over the just created connection...
        HSL::send $hsl "<190> Webmail Client Source IP: [IP::client_addr]" 
    } 
}

    Cheers, Kai