A VPX virtual appliance supports certificates of 512 or more bits, up to the following sizes:

• 4096-bit server certificate on the virtual server
• 4096-bit client certificate on the service
• 4096-bit CA certificate (includes intermediate and root certificates)
• 4096-bit certificate on the back-end server
• 4096-bit client certificate (if client authentication is enabled on the virtual server)

The following is the behavior on ADC SDX appliance:

• If VPX instance has at least one SSL chip assigned to it, then it supports certificates as supported by a MPX appliance
• if VPX instance has NO SSL chip assigned to it then it supports certificates as supported by a VPX appliance

Note: From Citrix ADC 13.0 build 79.64 and onwards we support 4096 client certificates on VPX

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