[pavornyoh]

Yes it is common for an employer to ask you to sign a non-compete. For example, an employee at Wipro who is working on a client's project say Pitney Bowes cannot come work for Pitney Bowes directly on that same project. He / She can get sued if there are agreements in place.

[WilandOr1903]

Yes, I recognize it's quite common to sign a non-compete, my question was specifically about whether it was common to include vendors in the agreement.

[pavornyoh]

Yes, it is.