Upper limit for autoincrement primary key in SQL Server

Question

What is the upper limit for an autoincrement primary key in SQL Server? What happens when an SQL Server autoincrement primary key reaches its upper limit?

Answer 1

DBCC CHECKIDENT (SomeTable, RESEED, 1)

This resets the identity to 1 on table 'SomeTable'

Not sure if this is the best way to do this.