CCNA2 e esercizi

[relay]

Ciao A tutti, sto studiando la ccna 2 e non riesco a capire alcuni esercizi.Tipo:
In the network shown in the graphic( three point-to-point links), three bits were borrowed from the host portion of a Class C address. How many valid host addresses will be unused on the three point-to-point links combined if VLSM is not used?
3
4
12
36
84
180
Grazie!

[ghira]

Ciao A tutti, sto studiando la ccna 2 e non riesco a capire alcuni esercizi.Tipo:
In the network shown in the graphic( three point-to-point links), three bits were borrowed from the host portion of a Class C address. How many valid host addresses will be unused on the three point-to-point links combined if VLSM is not used?
3
4
12
36
84
180
Grazie!

ok. stanno usando /27 per le reti. 32 indirizzi per ciascuna rete, di cui 30 validi.
totale 90 per le tre reti point-to-point. meno 6 che stai usando. 84 "unused".