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Forum Discussion

Patrick_Chang_7's avatar
Patrick_Chang_7
Historic F5 Account
Apr 08, 2009

What is max length of SSL key we can use on LTM?

Can I use an SSL Cert with a 4096 bit long key? If not, what needs to be adjusted to make this work? Thanks.
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2 Replies

  • Steve_87232's avatar
    Steve_87232
    Icon for Nimbostratus rankNimbostratus
    Oct 20, 2009
    Anyone have an update on this? Does 10.x support 4096? I can't seem to verify the answer.
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Oct 20, 2009
    Hi Steve,

     

     

    Apparently for client or server SSL, you can use certs/keys larger than 2048 bits if you use software SSL decryption:

     

     

     

    From case C564817:

     

    You can specify a cipher string of "DEFAULT:!NATIVE" and the "!NATIVE" will rule out using the acceleration card and just use software.

     

     

     

     

    This is also noted in SOL10580:

     

     

    SOL10580: The SSL key size is limited when using hardware acceleration

     

    https://support.f5.com/kb/en-us/solutions/public/10000/500/sol10580.html

     

     

    If you open a case with F5 you can ask to have your request added to CR124105.

     

     

    Aaron