寫出下列網(wǎng)絡(luò)掩碼的比特形式: a.255.255.192.0 b.255.192.0.0 c.255.255.224.0 d.255.255.255.0
用點(diǎn)分十進(jìn)制記法改寫下列掩碼:
a.255.255.255.248 b.255.255.255.224 c.255.255.248.0