An interviewer will ask you this question to determine the scope of your previous work and whether you have the experience necessary to manage a network similar in scale to theirs. While companies recognize that you can develop your skills and grow into the responsibility the job requires, they prefer to hire candidates who have already performed work similar to what they will be doing for their organization. When responding to the size of the networks you have managed, be honest and describe them accurately. If the networks were smaller than those of this organization, describe what you learned in your previous roles that will contribute to your ability to manage the company's network. Suppose the size of the networks you previously managed exceed that of the company's. In that case, you can discuss techniques you learned which would help improve the company's network operations and save them money.