X0306 4 2017-02-15 0 0001484504 Gigamon Inc. GIMO 0001577354 Merchant Shehzad C/O GIGAMON INC. 3300 OLCOTT STREET SANTA CLARA CA 95054 0 1 0 0 Chief Technology Officer Common Stock 2017-02-15 4 M 0 7475 0.00 A 53121 D Common Stock 2017-02-15 4 F 0 4235 34.95 D 49435 D Performance-Based Restricted Stock Units 0.00 2017-02-15 4 M 0 7475 0.00 D Common Stock 7475 22425 D Represents the shares vested upon the achievement of certain performance-based vesting criteria of the performance-based restricted stock units ("PRSUs") reported in a Form 4 filed on February 17, 2016. The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units and PRSUs. Includes 549 shares acquired by the Reporting Person under the Issuer's 2013 Employee Stock Purchase Plan on February 15, 2017. 25% of the PRSUs vested on February 15, 2017 with 1/16th of the shares to vest on the 15th of each of May, August, November and February thereafter. Represents the balance of PRSUs held as restated to reflect the achievement of approximately 150% of performance criteria in the PRSU grant reported in a Form 4 filed on February 17, 2016. /s/ Paul Shinn, Attorney-in-Fact 2017-02-17