That is a code that basically specifies the size of a network or subnet. It is basically equivalent to the subnet mask, but written differently.
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Visafone
an IP address is represented as A.B.C.D /n, where "/n" is called the IP prefix or network prefix. The IP prefix identifies the number of significant bits used to identify a network. For example, 192.9.205.22 /18 means, the first 18 bits are used to represent the network and the remaining 14 bits are used to identify hosts.
an IP address is represented as A.B.C.D /n, where "/n" is called the IP prefix or network prefix. The IP prefix identifies the number of significant bits used to identify a network. For example, 192.9.205.22 /18 means, the first 18 bits are used to represent the network and the remaining 14 bits are used to identify hosts.
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When we express an IPv4 network address, we add a prefix length to the network address. The prefix length is the number of bits in the address that gives us the network portion. For example, in 172.16.4.0 /24, the /24 is the prefix length - it tells us that the first 24 bits are the network address. This leaves the remaining 8 bits, the last octet, as the host portion.
In either IPv4 or IPv6, a network address is the first address in the network IP range. It has all zeroes in the host field, when written in binary. It cannot be assigned to a host device. It appears in a router's routing table to identify the network. For example:O 148.43.200.80/28 [110/586] via 148.43.200.30, 00:03:07, Serial0/0/0This shows that network 148.43.200.80 is reachable out interface s0/0/0. It is a /28 network, meaning 16 total IPv4 addresses. 148.43.200.80 is the first one, "the network address," and as said before, can't be assigned to a host device. This network would extend to 148.43.200 95, which would be the broadcast address for the network (all 1s in the binary host field), and also can't be assigned to a host.All the addresses in the network share the network prefix. It is simply the network portion of the address, in binary. Since these are /28 addresses, the network prefix is 28 bits long...the first 28 bits of the 32 bit address. For these addresses in the example network, the network prefix is (in bold):10010100.00101011.10001000.01010000. The remaining four bita at the end are the host bits, or host field, or host number (all the same thing).People will write this network prefix like so: 148.43.200.80 /28. Now 148.43.200.80 is the network address, so it's easy to see where the confusion comes from. You pretty much have to understand from context whether they're talking about the network prefix or the network address.Some people will refer to the CIDR prefix...the /28...just as the prefix, or even the network prefix, but it really is just a way to represent the subnet masking. It says that the first 28 bits of the address in question are the network bits, and will be identical for any IP in this network.
It represents the network portion
O2 in the United Kingdom.
205.61.128.79