Computer Networks · M2 · revision
The mistakes that change a correct method into a wrong answer
Last-day revision
M2 · use after the lessons and worked examples
| Trap | Correct action |
|---|---|
| Use 500 frames/s directly as G | First multiply by frame time |
| S and success probability treated as identical | Success probability per attempt is S/G |
| kbps converted using 1024 | Use decimal network rates unless explicitly specified otherwise |
| All subnet blocks assumed to change only last octet | Locate changing mask octet; /20 changes the third |
| First address means first usable | First address is network; first usable is network+1 |
| Subtract two from requested total addresses | Only ordinary usable-host count excludes the boundary two |
| Any consecutive networks aggregated blindly | Check power-of-two size and alignment |
| Two :: compressions in one IPv6 address | Use :: at most once |
| Dijkstra used on negative edges | Use Bellman–Ford when appropriate |
| Undirected reverse edges added to directed PYQ | Follow printed arrows only |
| All Bellman–Ford passes treated as identical conventions | State in-place or previous-pass method; do not mix |
| RIP metric 16 described as reachable | 16 means unreachable |
| ARP asked for remote server MAC | Resolve local gateway/next-hop MAC |