NetScout Systems, Inc.
I NCENTIVE S TOCK O PTION A GREEMENT —I NCORPORATED T ERMS AND C ONDITIONS
1. Grant Under Plan . This option is granted pursuant to and is governed by the Company’s 1999 Stock Option and
Incentive Plan (the “ Plan ”) and, unless the context otherwise requires, terms used herein shall have the same meaning as in the
2. Grant as Incentive Stock Option . This option is intended to qualify as an incentive stock option under Section 422 of
the Internal Revenue Code of 1986, as amended, and the regulations thereunder (the “ Code ”).
3. Vesting of Option if Employment Continues . If the employee whose signature appears on the cover page hereof (the
“Employee”) has remained continuously employed by the Company through the dates listed on the vesting schedule set forth
on the cover page hereof, the Employee may exercise this option for the number of shares of Common Stock indicated on the
cover page hereof. If an installment of this option becomes exercisable for a fraction of a share at any time during the dates
listed on the vesting schedule on the cover page hereof (including as a result of adjustment provisions contained in the Plan),
such installment shall be deemed exercisable only with respect to whole shares, rounded down. The option for any fractional
shares aggregated throughout the vesting period (to the extent they result in a whole number of shares) shall become
exercisable when the last installment of the option vests. To the extent aggregated fractional shares result in fractional shares,
such shares shall be cashed out at fair market value. Notwithstanding the foregoing, the Board may, in its discretion, accelerate
the date that any installment of this option becomes exercisable. The foregoing rights are cumulative and (subject to Sections 4
or 5 hereof if the Employee ceases to be employed by the Company) may be exercised only before the date which is ten years
from the date of this option grant.
4. Termination of