Getting a high percentage rate of SSL decode failures and "Unknown cipher suite" error messages in the TIM log.

Products

• CA Application Performance Management Agent (APM / Wily / Introscope)
• INTROSCOPE

Issue/Introduction

 The "TIM SSL Servers" page shows about 90% of "Connections with decode failures" out of "Total connections", and more than half of them are "Unsupported cipher suites". 

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  The TIM log ("timlog.txt") shows repeated warning messages like the one below:

  3587 ! Warning: w20: sslinterface: network_process_packet: error 10 (unsupported ciphersuite), conn 277107, packet 60792088, [<ip_address>]:39919->[<ip_address>]:443; ignoring further data

 

Cause

DH/DHE (Diffie-Hellman) cipher suites are not supported by TIM.

Environment

Web Server is running on WIN2012 R2. APM/TIM 10.0 installed. TIM is not on a MTP.

Resolution

  Any DH/DHE (Diffie-Hellman) cipher suites should be taken out of cipher suites configuration on the Web Server, so that packets containing those cipher suites do not get forwarded  to TIM. 

  * Cipher Suites configuration on the web server.

Initially:

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After DH/DHE cipher suites were removed:

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 After the above change is made (mainly in the "SSL Cipher Suite Order" section), there are no longer "Unsupported cipher suites" messages.

Additional Information

 TEC1667615: Which Cipher Suites are supported CEM/TIM for decoding SSL hosted applications and how can I check those against the Ciphers installed on my web servers?