Answer:

There are two ways to renew/extend an existing certification:

1. By retaking and passing the last exam you took to achieve that certification; or,
2. By achieving/renewing a higher-level certification listing the existing certification as a prerequisite.

Example:

For example, let's assume you have already achieved the F5 Certified Administrator for BIG-IP (F5-CA, BIG-IP) certification by passing both exam 101 and 201.

• By rule #1, you may renew your F5-CA by retaking and passing exam 201 - the last exam you took to achieve the certification.
• By rule #2, you may extend your F5-CA by achieving any F5 Certified Technology Specialist (F5-CTS) certification as all of them list the F5-CA as a prerequisite.

NOTE: It is important to understand that rule #2 is based on achieving a certification, not simply passing an exam.  In most cases, this difference is not relevant; however, in some cases it is very important.  For instance, passing exam 301a does not result in a certification, it simply makes you eligible for exam 301b.  You must pass exam 301b to achieve the F5-CTS, BIG-IP LTM certification, which would then trigger rule #2 and automatically renew/extend the prerequisite F5-CA.