Forum Discussion

Mate_132781's avatar
Mate_132781
Icon for Cirrostratus rankCirrostratus
Mar 30, 2016

SSL Re-Encryption - No SSL traffic on server side

Hi,

 

I configured SSL re-encryption on F5 virtual edition, but I don't see SSL traffic on server side.

 

Client correctly connects to outside IP of F5, but when I create TCPDUMP there is no SSL traffic on server side

 

I'm using self signed certificates on client side and default sslserver profile on server side.

 

I belive that problem is not on SSL level because there is nothing in log and f5 even does not start SSL handshake...

 

On other side, when I try with openssl coman, SSL session is correctly setted up.

 

pls help.

 

  • Thank you for hint! :-)

     

    To be sure I disabled HTTPS monitor on BIG-IP and after that there was no any traffic to server. After starting HTTPS connection from client I noticed that F5 used outside IP adress (one to which client connected) as a source IP address torward server. SNAT auto-map was enabled on VS.

     

    After that I created SANT pool with inside IP address of F5, associate it with VS and now everything is working.

     

    Monitor traffic confused me in TCPDUMP.

     

    Thanks for help.

     

  • How do you determine presence or no presence of SSL traffic? Do you open your capture file and expect to see TLS/SSL messages? SSL/TLS messages, such as CLIENTHELLO are only seen after you import the SSL private key to WireShark (private key from end-server). Before that is done, all traffic is encrypted, and can only be seen as TCP 443 stream.

     

    On a very basic level, I hope you're aware that if you configure serverssl profile, that configuration itself doesn't re-encrypt traffic before forwarding it to end-server, unless your end-server listener is SSL-enabled, and correctly presents a SSL certificte. The serverssl profile configuration only enables F5 itself to act as a client during SSL handshake phase.

     

    • Mate_132781's avatar
      Mate_132781
      Icon for Cirrostratus rankCirrostratus
      Access to WEB servers is working and pure HTTP is disabled on application. I'm aware of things you wrote. Thank you very much for help. :-)
  • How do you determine presence or no presence of SSL traffic? Do you open your capture file and expect to see TLS/SSL messages? SSL/TLS messages, such as CLIENTHELLO are only seen after you import the SSL private key to WireShark (private key from end-server). Before that is done, all traffic is encrypted, and can only be seen as TCP 443 stream.

     

    On a very basic level, I hope you're aware that if you configure serverssl profile, that configuration itself doesn't re-encrypt traffic before forwarding it to end-server, unless your end-server listener is SSL-enabled, and correctly presents a SSL certificte. The serverssl profile configuration only enables F5 itself to act as a client during SSL handshake phase.

     

    • Mate_132781's avatar
      Mate_132781
      Icon for Cirrostratus rankCirrostratus
      Access to WEB servers is working and pure HTTP is disabled on application. I'm aware of things you wrote. Thank you very much for help. :-)
  • Thank you for hint! :-)

     

    To be sure I disabled HTTPS monitor on BIG-IP and after that there was no any traffic to server. After starting HTTPS connection from client I noticed that F5 used outside IP adress (one to which client connected) as a source IP address torward server. SNAT auto-map was enabled on VS.

     

    After that I created SANT pool with inside IP address of F5, associate it with VS and now everything is working.

     

    Monitor traffic confused me in TCPDUMP.

     

    Thanks for help.