Are you making a HUGE mistake at your current job by not networking consistently? Everyone knows how important it is to network when you're looking for a job, but many just stop once they move into a new role.
The best time to network and the time when its most often overlooked is while you're still on the job.
If you want to put yourself in a position where you're going to be the first person up for a promotion or become an integral part of the team when you're at a new job, you've got to network with the people that you work with and not just the people at your level.
It's easy to connect with the people at your level.
Maybe your desks are in the same area of the office or maybe you even knew each other for school. Forming connections with peers comes more naturally to must people who are at least relatively friendly and open to meeting new people. This is definitely important and I absolutely encourage you to form relationships with your immediate peers. Down the line, they ARE going to be the best people to help you in your career and present opportunities for advancement.
Its much more challenging for most to become close and familiar with those a level or two above them if they're not your immediate advisor.
The person that you directly report to is obviously going to be an important person for you to form a relationship with because they may have immediate control over your career trajectory for now. However, the other people you want to deliberately form relationships are the people on the same level in other areas of the company on the same level with your boss AND those above him or her. Why? They may have an influence on your boss and therefore your career trajectory. Moreover, there may be occasions when they could potentially have the opportunity to choose you to help them with an opportunity that you wouldn't otherwise be the first consideration for.
Some people may be thinking "but I'm happy at my current job, I don't need a change." Well then you should DEFINITELy be forming these connections. There's absolutely no better time because you're going to naturally be more positive about your job, your boss, your colleagues – thats just basic likability. People are more eager to connect with someone who is upbeat and positive.