The introduction of efficient bridges (Layer 2 switches) has made it easy to build very large LANs. There are some advantages to letting a LAN grow very large instead of cutting it into separate smaller LANs that are separated by routers:
Fewer routers are needed. High-capacity routers are more costly than bridges.
Many administrators feel that routers are more complicated to configure than bridges.
Bridges forward traffic faster than routers (although current Layer 3 switcheswhich are routersare fairly fast).
Keep in mind that by definition, a LAN contains only hubs (Layer 1 wiring concentrators) and bridges (Layer 2 switches). When you go through a router, you have left a LAN.
Building a big physical ...