X0306 4 2021-02-01 0 0001048695 F5 NETWORKS, INC. FFIV 0001720763 SPRAGUE KARA LYNN C/O F5 NETWORKS, INC. 801 5TH AVENUE SEATTLE WA 98104 0 1 0 0 EVP & GM, Application Services Common Stock 2021-02-01 4 M 0 3280 0.00 A 22735 D Common Stock 2021-02-01 4 F 0 1314 196.35 D 21421 D Restricted Stock Unit 0.00 2021-02-01 4 M 0 1244 0.00 D Common Stock 1244 3732 D Restricted Stock Unit 0.00 2021-02-01 4 M 0 857 0.00 D Common Stock 857 9431 D Restricted Stock Unit 0.00 2021-02-01 4 M 0 466 0.00 D Common Stock 466 1396 D Restricted Stock Unit 0.00 2021-02-01 4 M 0 713 0.00 D Common Stock 713 4991 D Shares acquired upon vesting of the November 1, 2017, November 1, 2018, November 1, 2019 and November 2, 2020 awards of service-based Restricted Stock Units. Each Restricted Stock Unit represents a contingent right to receive one share of F5 Networks, Inc. Common Stock on the vest date. This November 1, 2017 award of service-based Restricted Stock Units vests twenty five percent (25%) on November 1, 2018, and the remaining seventy five percent (75%) vests in twelve equal quarterly increments beginning February 1, 2019. If the reporting person continues to serve as an officer of the Company on the vest date, the corresponding number of shares of Common Stock of F5 Networks, Inc. will be issued to the reporting person on the vest date. This November 2, 2020 award of service-based Restricted Stock Units vests in twelve equal quarterly increments beginning February 1, 2021. This November 1, 2018 award of service-based Restricted Stock Units vests in twelve equal quarterly increments beginning February 1, 2019. This November 1, 2019 award of service-based Restricted Stock Units vests in twelve equal quarterly increments beginning February 1, 2020. /s/ Scot F. Rogers by Power of Attorney 2021-02-03