There importance of one’s professional network cannot be overstated. Being smart and tenacious isn’t always enough, and as Michelle Awuku-Tatum reports in a post for Black Enterprise, recent data from the Executive Leadership Council suggests that 31 percent of African American female executives cite weak networks as a source of their struggles to climb the corporate ladder.

As Awuku-Tatum writes, it’s “important to take stock of who is in your circle, who is supporting you and who is advocating for you when you are not in the room,” and while she’s writing mainly about leaders, her picks for the “3 Critical Relationships for Career Survival” apply across the board.

First up, she says, is an “internal adviser or mentor.” This person can be a manager, a colleague, or even a peer; the important thing is that he or she has an understanding of company politics and the ability to help you “decode many of the things that are left unsaid,” as Awuku-Tatum writes. The idea is that this adviser will help you move ahead with ideas in the best way possible.

Next is the “internal advocate,” or if you’re lucky, “advocates.” This is someone (or a group of people) who are truly invested in your success, and who occupy positions of power enabling them to promote your ideas and sing your praises. As Awuku-Tatum writes, these individuals — managers, executives, board members, etc. — can be difficult to find, but they’re invaluable.

While it’s crucial to seek guidance from those within your firm, Awuku-Tatum believes it’s sometimes helpful to take a step back and get some fresh perspective. Hence the third person you should have in your network: the “external advisor or mentor.” This person might be a former mentor or colleague, but regardless of how you know them, it’s essential that they provide an unbiased opinion of what’s going on at your company and perhaps offer insights on industry best practices and trends.

“You want someone who is not going to hold their tongue when you are clearly in the wrong, who will go the extra mile to help you figure out how to course correct and encourage you to try different strategies,” Awuku-Tatum writes.