Common topologies:
Star (all connect to central switch — modern standard),
Bus (legacy coax),
Ring (legacy token ring),
Mesh (redundant paths — data centers, WAN),
Hybrid (combination).
Modern LANs use hierarchical star topology (access → distribution → core). Data centers use spine-leaf (highly redundant mesh). WAN uses partial mesh (cost-effective redundancy). Physical vs. logical topology: logical can differ from physical (ring protocol over physical star).