Cisco – Leupers.net

# Bits	# Hosts	Netmask	Cisco Mask	Notes
/4	268435456	240.0.0.0	15.255.255.255
/5	134217728	248.0.0.0	7.255.255.255
/6	67108864	252.0.0.0	3.255.255.255
/7	33554432	254.0.0.0	1.255.255.255
/8	16777216	255.0.0.0	0.255.255.255	class A network
/9	8388608	255.128.0.0	0.127.255.255
/10	4194304	255.192.0.0	0.63.255.255
/11	2097152	255.224.0.0	0.31.255.255
/12	1048576	255.240.0.0	0.15.255.255
/13	524288	255.248.0.0	0.7.255.255
/14	262144	255.252.0.0	0.3.255.255
/15	131072	255.254.0.0	0.1.255.255
/16	65536	255.255.0.0	0.0.255.255	class B network
/17	32768	255.255.128.0	0.0.127.255
/18	16384	255.255.192.0	0.0.63.255
/19	8192	255.255.224.0	0.0.31.255
/20	4096	255.255.240.0	0.0.15.255
/21	2048	255.255.248.0	0.0.7.255
/22	1024	255.255.252.0	0.0.3.255
/23	512	255.255.254.0	0.0.1.255
/24	256	255.255.255.0	0.0.0.255	class C network
/25	128	255.255.255.128	0.0.0.127
/26	64	255.255.255.192	0.0.0.63
/27	32	255.255.255.224	0.0.0.31
/28	16	255.255.255.240	0.0.0.15
/29	8	255.255.255.248	0.0.0.7
/30	4	255.255.255.252	0.0.0.3
/31	point to point links only
/32	1	255.255.255.255	single IP address	use host notation

Note:
The number of usable hosts is always two less than the overall number of hosts in the sub-network.

Schlagwort: Cisco