The routing vs. switching wars of the mid-1990s pitted routing kingpin Cisco against virtually every other competitor in the enterprise space: Bay Networks, 3Com, and Cabletron, which all promoted a flat, Layer 2 switched infrastructure.
At its root, the debate centered around whether businesses should construct hierarchical router networks in order to better segment and administer traffic and workgroups; or if flat Layer 2 infrastructures with virtual LANs establishing broadcast domains did the same thing, only less expensively.
The stand-off also ushered in technologies such as the routing hub -- or "Rub" -- and the Layer 3 switch. It also produced such innovations as Ipsilon's IP Switching, and Cisco's Tag Switching for service providers, one of the early incarnations of what is now known as MPLS.
The debate also made for memorable marketing slogans, such as Bay Networks' "Switch when you can, route when you must."
But crafty slogans weren't enough to keep the market from moving to Cisco. Because of its ability to meld de facto standard routing with LAN switching, deft marketing and a bit of a price compromise, Cisco was able to lock up the Layer 3 switching market to complement its dominance in routers.
Bay, 3Com and Cabletron put up a valiant fight but in the ensuing years, these companies vanished or were marginalized as bit players in enterprise networking.