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rosarra's avatar
rosarra
Icon for Altocumulus rankAltocumulus
Jun 13, 2022

Random Handshake failed

Hello,

I know this problem has already been addressed in other posts but I don't find a solution to my problem. In a configuration with a VS running ssl decryption everything works correctly but sometimes in random mode and with increasing frequency depending on the amount of traffic I see failed handshakes coming in. The source addresses are part of an AWS CDN and randomly return this type of error while normally they seem to work correctly. I therefore exclude a certificate problem because otherwise it would not work at all. Any ideas where I can look for the cause?

tmm3[11083]: 01260013:6: SSL Handshake failed for TCP 70.132.17.36:31720 -> 10.xxx.xx.xxx:443

application delivery
  • neeeewbie's avatar
    neeeewbie
    Icon for MVP rankMVP
    Jun 17, 2022

    I guess this problem relate to cipher suite 

    some device tried to ssl handshake with not cipher supported by F5 

    • rosarra's avatar
      rosarra
      Icon for Altocumulus rankAltocumulus
      Jun 17, 2022

      Unfortunately, I think it is more complicated. I did a ssldump of the correct and failed connections.
      It seems that at some point the connection is reset by the source and this is interpreted by F5 as Handshake failed. Probably because it happens during the certificate exchange phase. Is this possible?

      See the ssldump here attached.

       

  • neeeewbie's avatar
    neeeewbie
    Icon for MVP rankMVP
    Jun 21, 2022

    you can see "cipherSuite Unknown value 0x9d" 

    could you change cipher list to "all" in ssl profile (client and server )?