Subnet Masking And Addressing :: essays research papers

Ok, this explains subnet sumressing which is utilitarian if you run a s enkindlener, a firew all told, a router or anything else that is bound to IP subnet channelressing. Note that this only describes IPv4 subnets. Reading double star values      Normally, you read binary numbers bytewise (8 bit wise). Start at the last bit, bit 0. If it is 1, add 20 to your number, else add 0. Then the next bit, bit 1, If it is 1, add 21 (2) to your number, If bit 3 is 1 add 22 (4) to your number, if bit 4 is 1 add 23 (8) to your number ... if bit 8 is 1 add 27 (128) to your number. You see, the base is always 2 because it can be either 0 or 1. Example 1 10100100 = 27+0+25+0+0+0+22+0+0 = 164 Example 2 11111111 = 27+26+25+24+23+22+21+20 = 255 Thats it Now to subnet addressing.     When you adduce a host including a subnet (example nmap), you do it equal this 1.2.3.4/24, where /24 is the subnet. Lets down a look at what this means an IP address is a 32 bi t address. It is divided into 4 bytes (each 8 bits meaning they can be 0 to 255) in general notation00000001 00000010 00000011 00000100 = "1.2.3.4"now, IP uses unrivaled part of this address to specify which Net it is on. Most of the time, this is a somatogenetic Net like an ethernet LAN that is linked to the internet. Nets that link to the internet wreak dedicated IPs for each of their hosts from the IANA.org. /24 means that the first 24 bits are the Net address and the remaining 8 bits are the Host address. This looks like this Net 000000010000001000000011 Host 00000100 Meaning, we are on the net 1.2.3.0 (0 used as a wildcard here) and on the host 4 of 256.      SUBNET MASK In this case, the subnet secrete would be 255.255.255.0. A subnet mask is created simply by filling all NET address bits with 1 and the HOST bits with 0. (11111111 = 255). There are 4 "Classes" on the Internet, which are the standard Subnets.      *Cl ass A "0" + 7 net bits + 24 host bits, hosts 0.0.0.0 to 126.255.255.255 Net IDs 0 0000000 to 0 1111111 (which is 127 => 127.0.0.0 speechless for local loopback)      *Class B "10" + 14 net bits + 14 host bits, hosts 128.