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Eddy_161863's avatar
Eddy_161863
Icon for Nimbostratus rankNimbostratus
Apr 13, 2016

Receive string '0' on f5 LTM

Hi ,

 

I'm trying to understand a situation on f5. So for one of my monitors, I have the receive string setup as '0' (zero). When I checked the TCP trace, it's returning a 401 error for the send string I'm checking but the health check is showing green on f5. Can anyone tell me why it is green on f5 when it should fail. does putting '0' as a receive string has a special meaning?

 

Thanks in advance for your help.

 

application delivery
LTM

2 Replies

  • Arie's avatar
    Arie
    Icon for Altostratus rankAltostratus
    Apr 13, 2016

    The monitor checks for the presence of a "0" in the response. Since "401" contains a "0" the validation check will pass. You'll want to be a bit more specific with the receive string (e.g. "200 OK").

     

  • Arie's avatar
    Arie
    Icon for Altostratus rankAltostratus
    Apr 13, 2016

    What different numbers did you try? Are you sure they're not found in the HTTP headers?

     

    What happens if you use a string of which you're sure it's not going to be found as part of the response?