Technology Innovation Centre CATC Birmingham Subnetting CCNA 1

Technology Innovation Centre CATC Birmingham Subnetting CCNA 1 v 3 H. Carpentier John Higgins CCNA 1 v 3 2004 http: //web. tic. ac. uk/staff/carpentier

TCP/IP IPv 4 Addresses. John Higgins CCNA 1 v 3 2004 2

TCP/IP IPv 4 Address structure. • 32 bit binary number. • Divided into four 8 bit octets. • Each octet expressed as a denary/decimal number. John Higgins CCNA 1 v 3 2004 3

Dotted Decimal 32 Bit Binary to Dotted Quad (Dotted decimal) Format. 1100000010101000000010 11000000. 10101000. 00001010. 00000010 192. 168. 10 John Higgins CCNA 1 v 3 2004 . 2 4

Address Classes. First Octet Binary First Octet decimal Address Range 1. ### 126. ### Class A 0 XXXXXXX. ### Class B 10 XXXXXX. ### 128. ### 191. ### Class C 110 XXXXX. ### 192. ### 223. ### Class D 1110 XXXX. ### 224. ### 239. ### John Higgins CCNA 1 v 3 2004 5

TCP/IP Address Examples. 203. 10. 1. 0 Class C 47. 0. 0. 0 Class A 64. 64. 2 Class A 150. 33. 20 Class B John Higgins CCNA 1 v 3 2004 6

Network+Host IP Address = NETWORK + HOST Class A NETWORK. HOST Class B NETWORK. HOST Class C NETWORK. HOST John Higgins CCNA 1 v 3 2004 7

Subnet Mask. Indicates which part of an ip address is the network part, and which part is the host. The subnet mask is 32 bits long, consisting of a string of ones starting from the left to indicate the length of the network portion, with the remaining bits set to zero. John Higgins CCNA 1 v 3 2004 8

Subnet Mask Class B address and default mask. Address 151. 100. 111 Subnet mask 255. 0. 0 ip address 151 . 100 . 111 10010111 . 01100100 . 01101011 255 . 000 11111111 . 0000 network . host subnet mask John Higgins CCNA 1 v 3 2004 9

IP addresses Special Cases. 127. 0. 0. 1 Ethernet local loop-back address on Ethernet NICs. Private addresses reserved for internal use within an organisation ( RFC 1918 ). IP packets with private Addresses Not forwarded in the internet. 10. 0 10. 255 172. 16. 0. 0 172. 31. 255 192. 168. 0. 0 192. 168. 255 subnet mask 255. 0. 0. 0 subnet mask 255. 240. 0. 0 subnet mask 255. 0. 0 John Higgins CCNA 1 v 3 2004 10

TCP/IP Layer-7 connectivity Layer-3 connectivity Physical connections and addressing John Higgins CCNA 1 v 3 2004 11

IPv 4 Subnetting. The logical division of one network address to give multiple usable subnet work addresses. John Higgins CCNA 1 v 3 2004 12

Class B Subnetting. John Higgins CCNA 1 v 3 2004 13