She is most famous for her invention of the Spanning Tree Protocol (STP), which is fundamental to the operation of network bridges, while working for Digital Equipment Corporation, thus earning her nickname "Mother of the Internet".

She also made large contributions to many other areas of network design and standardization: for example, enabling today's link-state routing protocols, to be more robust, scalable, and easy to manage.

Perlman was elected a member of the National Academy of Engineering in 2019 for contributions to Internet routing and bridging protocols.

[6][7] More recently she has invented the TRILL protocol to correct some of the shortcomings of spanning trees, allowing Ethernet to make optimal use of bandwidth.

During her school years Perlman found math and science to be “effortless and fascinating”, but had no problem achieving top grades in other subjects as well.

She was given her first paid job in 1971 as part-time programmer for the LOGO Lab at the (then) MIT Artificial Intelligence Laboratory, programming system software such as debuggers.

[11] Working under the supervision of Seymour Papert, she developed a child-friendly version of the educational robotics language LOGO, called TORTIS ("Toddler's Own Recursive Turtle Interpreter System").

During research performed in 1974–76, young children—the youngest aged 3½ years, programmed a LOGO educational robot called a Turtle.

[14] Afterwards, she was inspired to make a new programming language that would teach much younger children similar to Logo, but using special "keyboards" and input devices.

[15] Her doctoral thesis on routing in environments where malicious network failures are present serves as the basis for much of the work that now exists in this area.

[11] After graduation, she accepted a position with Bolt, Beranek, and Newman (BBN), a government contractor that developed software for network equipment.

While working for BBN, Perlman made an impression on a manager for Digital Equipment Corp and was offered a job, joining the firm in 1980.

During her time working at Digital, she quickly produced a solution that did exactly what the team wanted it to; the Spanning Tree Protocol.

Her contributions to network security include trust models for Public Key Infrastructure, data expiration, and distributed algorithms resilient despite malicious participants.

Over the course of her career she has earned over 200 patents, 40 of them while working for Sun Microsystems, where in 2007 she held the title of Distinguished Engineer.

Perlman said that the benefits of the protocol amount to the fact that "you don't have to worry about topology" when changing the way a LAN is connected.

[19] The Open Shortest Path First (OSPF) protocol relied in part on Perlman's research on fault-tolerant broadcasting of routing information.

[12] When standarizing her work on TRILL, a combined bridging and routing protocol that proposes to supersede STP, she included version 2 of the earlier "Algorhyme":[24] I hope that we shall one day see A graph more lovely than a tree.