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Subneting Dividing large network into small network for efficiently utilize of the Ip address. Converting host bits into network bits. Efficient utilize the network. Optimize of the network. Good security to hosts and network. Good performance. Subnetting is also called as FLSM(Fixed length subnet mask).

Three ways we do subnetting Requirement of networks. Requirement hosts. Cisco notation.

VALUES IN SUBNET MASK Bit Value Mask VALUES IN SUBNET MASK Bit Value Mask

POWER TABLE 2 1 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

6 Example – 1 One bit masking is Invalid, You are not getting any networks when you convert 1 host bit to network bit. Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Subnet =2 n – 2 =2 1 – 2 =2 – 2 =0 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxx HELP

7 Example – 2 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 1 – 2 =2 – 2 = 0 Hosts/Subnet In this case, You are not getting any host when you convert 7 host bit to network bit. Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Subnet =2 n – 2 =2 7 – 2 =128 – 2 =126 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

8 Example – 3 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 0 – 2 =0 – 2 = -2 Hosts/Subnet In this case, You are not getting any host when you convert 8 host bit to network bit. Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Subnet =2 n – 2 =2 8 – 2 =256 – 2 =254 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

9 Requirement of Hosts is 40 ? Example – 1 Re No. of Subnet =2 n – 2 (-2 is for First & Last Subnet Range) =2 2 – 2 =4 – 2 =2 Subnet Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Host =2 h – 2  Req. of Host =2 6 – 2  40 (-2 is for Network ID & Broadcast ID) =64 – 2 =62 Hosts/Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

10 x Example – 1 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – If you convert 2 Host Bits to Network Bits 2 Subnet & 62 Hosts/Subnet Customize Subnet Mask Subnet Range to to If you convert 2 Host Bits to Network Bits 2 Subnet & 62 Hosts/Subnet Customize Subnet Mask Subnet Range to to

11 Requirement of Hosts is 2 ? Example – 2 No. of Subnet =2 n – 2 (-2 is for First & Last Subnet Range) =2 6 – 2 =64 – 2 =62 Subnet Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Host =2 h – 2  Req. of Host =2 2 – 2  2 (-2 is for Network ID & Broadcast ID) =4 – 2 =2 Hosts/Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

12 x Example – 2 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – – –

13 Cisco / Notation Example – 1 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 3 – 2 =8 – 2 =6 Hosts/Subnet Class C : N.N.N.H(Requirement is 30 subnets) 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : /29 Extra Network Bits = 29 – 24 = 5 Put n value = 5 No. of Subnet =2 n – 2 =2 5 – 2 (-2 is for First & Last Subnet Range) =32 – 2 =30 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

14 Example – 1 (Continued…) Customize Subnet Mask = x x Valid Subnets – – – – – – Range of Networks Network IDBroadcast ID If you convert 5 Host Bits to Network Bits 30 Subnet & 6 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to If you convert 5 Host Bits to Network Bits 30 Subnet & 6 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to

15 Cisco / Notation Example – 2 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 4 – 2 =16 – 2 =14 Hosts/Subnet Class C : N.N.N.H(Requirement is 12 subnets) 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : /28 Extra Network Bits = 28 – 24 = 4 Put n value = 4 No. of Subnet =2 n – 2 =2 4 – 2 (-2 is for First & Last Subnet Range) =16 – 2 =14 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

16 x Example – 2 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – – – If you convert 4 Host Bits to Network Bits 14 Subnet & 14 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to If you convert 4 Host Bits to Network Bits 14 Subnet & 14 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to

17 Requirement of Networks is 2 ? Example – 1 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 14 – 2 =16384 – 2 =16382 Hosts/Subnet Class B : N.N.H.H(Requirement is 2 Subnets) 10xxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class B : No. of Subnet =2 n – 2  Req. of Subnet =2 2 – 2  2 (-2 is for First & Last Subnet Range) =4 – 2 =2 Subnet 10xxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

18 Example – 1 (Continued…) Customize Subnet Mask = x x Valid Subnets – Range of Networks Network IDBroadcast ID – – – If you convert 2 Host Bits to Network Bits 2 Subnet & Hosts/Subnet Customize Subnet Mask Subnet Range to to If you convert 2 Host Bits to Network Bits 2 Subnet & Hosts/Subnet Customize Subnet Mask Subnet Range to to

19 Requirement of Hosts is 126 ? Example – 2 No. of Subnet =2 n – 2 (-2 is for First & Last Subnet Range) =2 9 – 2 =512 – 2 =510 Subnet Class B : N.N.H.H 10xxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class B : No. of Host =2 h – 2  Req. of Host =2 7 – 2  126 (-2 is for Network ID & BroadcastID) =128 – 2 =126 Hosts/Subnet 10xxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

20 x Example – 2 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – – – If you convert 9 Host Bits to Network Bits 510 Subnet & 126 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to If you convert 9 Host Bits to Network Bits 510 Subnet & 126 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to

21 Cisco / Notation Example – 3 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 10 – 2 =1024 – 2 =1022 Hosts/Subnet Class B : N.N.H.H 10xxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class B : /22 Extra Network Bits = 22 – 16 = 6 Put n value = 6 No. of Subnet =2 n – 2 =2 6 – 2 (-2 is for First & Last Subnet Range) =64 – 2 =62 Subnet 10xxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

22 x Example – 3 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – – – If you convert 6 Host Bits to Network Bits 62 Subnet & 1022 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to If you convert 6 Host Bits to Network Bits 62 Subnet & 1022 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to

23 Requirement of Networks is 500 ? Example – 1 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 15 – 2 =32768 – 2 =32766 Hosts/Subnet Class A : N.H.H.H(Requirement is 500 Subnet) 0xxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class A : No. of Subnet =2 n – 2  Req. of Subnet =2 9 – 2  500 (-2 is for First & Last Subnet Range) =512 – 2 =510 Subnet 0xxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

24 x Example – 1 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – – – If you convert 9 Host Bits to Network Bits 510 Subnet & Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to If you convert 9 Host Bits to Network Bits 510 Subnet & Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to

25 Requirement of Hosts is ? Example – 2 No. of Subnet =2 n – 2 (-2 is for First & Last Subnet Range) =2 6 – 2 =64 – 2 =62 Subnet Class A : N.H.H.H 0xxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class A : No. of Host =2 h – 2  Req. of Host =2 18 – 2  (-2 is for Network ID & BroadcastID) = – 2 = Hosts/Subnet 0xxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

26 x Example – 2 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – – – If you convert 6 Host Bits to Network Bits 62 Subnet & Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to If you convert 6 Host Bits to Network Bits 62 Subnet & Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to

27 Cisco / Notation Example – 3 No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 12 – 2 =4096 – 2 =4094 Hosts/Subnet Class A : N.H.H.H 0xxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class A : /20 Extra Network Bits = 20 – 8 = 12 Put n value = 12 No. of Subnet =2 n – 2 =2 12 – 2 (-2 is for First & Last Subnet Range) =4096 – 2 =4094 Subnet 0xxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

28 x Example – 3 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets – – – – – – If you convert 12 Host Bits to Network Bits 4094 Subnet & 4094 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to If you convert 12 Host Bits to Network Bits 4094 Subnet & 4094 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to

29 Subnetting a subnet is called as Variable Length Subnet Mask VLSMs provide the capability to include more than one subnet mask within a major network VLSM

30 Netmetric is having 100 PC Netmetric– /24 – MCSE – CISCO – FIREWALL – MARKETING - MCITP Administrator’s requirement : Inter-department communication should not be possible ? Best Solution is : FLSM i.e. Subnetting Scenario

31 Scenario (…continued) NETMETRIC – MCSE – CISCO – Ccna – Ccnp – FIREWALL – ISA – Checkpoint – Net SQ – Clavister – Cisco PIX – MARKETING – PURCHASE – SALES – STOCK – MCITP Now we are also having sub departments

32 Administrator does not want inter-department communication in the sub departments ? Answer : You will use the subnet range to further divide it into smaller ranges, this time its Subnetting of a Subnet i.e. VLSM. Scenario (…continued)

33 Calculation of FLSM No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 5 – 2 =32 – 2 =30 Hosts/Subnet Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Subnet =2 n – 2  Req. of Subnet =2 3 – 2  5 (-2 is for First & Last Subnet Range) =8 – 2 =6 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

34 x FLSM (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = x Valid Subnets 224 If you convert 3 Host Bits to Network Bits 6 Subnet & 30 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to to If you convert 3 Host Bits to Network Bits 6 Subnet & 30 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to to

35 ZOOM Technologies – MCSE – CISCO – Ccna – Ccnp – FIREWALL – ISA – Checkpoint – Net SQ – Clavister – Cisco PIX – MARKETING –Purchase – Sales – Stock – MCITP Assigning of the Ranges – 1.63/ – 1.95/ – 1.127/ – 1.159/ – 1.191/27

36 Calculation of VLSM for CISCO Dept. No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 4 – 2 =16 – 2 =14 Hosts/Subnet Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Subnet =2 n  Req. of Subnet =2 1  2 =2=2 =2 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

37 VLSM (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = Valid Subnets – – If you convert 1 more Host Bit to Network Bit 2 Subnet & 14 Hosts/Subnet Customize Subnet Mask Subnet Range to to If you convert 1 more Host Bit to Network Bit 2 Subnet & 14 Hosts/Subnet Customize Subnet Mask Subnet Range to to

38 Assigning of the Ranges – 1.79/ – 1.95/28 NETMETIRC – MCSE – CISCO – Ccna – Ccnp – FIREWALL – ISA – Checkpoint – Net SQ – Clavister – Cisco PIX – MARKETING – Purchase – Sales – Stock – MCITP – 1.63/ – 1.127/ – 1.159/ – 1.191/ – 1.95/27

39 Calculation of VLSM for Firewall Dept. No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 2 – 2 =4 – 2 =2 Hosts/Subnet Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Subnet =2 n  Req. of Subnet =2 3  5 =8=8 =8 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

40 VLSM (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = Valid Subnets – – – – – – – – If you convert 3 more Host Bit to Network Bit 8 Subnet & 2 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to to to to If you convert 3 more Host Bit to Network Bit 8 Subnet & 2 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to to to to to

41 Assigning of the Ranges NETMETRIC – MCSE – CISCO – Ccna – Ccnp – FIREWALL – ISA – Checkpoint – Net SQ – Clavister – Cisco PIX – MARKETING – Purchase – Sales – Stock – MCITP – 1.63/ – 1.127/ – 1.159/ – 1.191/ – 1.95/ – 1.79/ – 1.95/ – 1.99/ – 1.103/ – 1.107/ – 1.111/ – 1.115/30

42 Calculation of VLSM for Solaris Dept. No. of Host =2 h – 2 (-2 is for Network ID & Broadcast ID) =2 3 – 2 =8 – 2 =6 Hosts/Subnet Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Subnet =2 n  Req. of Subnet =2 2  3 =4=4 =4 Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

43 VLSM (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = Valid Subnets – – – – If you convert 2 more Host Bit to Network Bit 4 Subnet & 6 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to If you convert 2 more Host Bit to Network Bit 4 Subnet & 6 Hosts/Subnet Customize Subnet Mask Subnet Range to to to to

44 Assigning of the Ranges NETMETRIC – MCSE – CISCO – Ccna – Ccnp – FIREWALL – ISA – Checkpoint – Net SQ – Clavister – Cisco PIX – MARKETING – Purchase – Sales – Stock – MCITP – 1.63/ – 1.127/ – 1.159/ – 1.191/ – 1.95/ – 1.79/ – 1.95/ – 1.99/ – 1.103/ – 1.107/ – 1.111/ – 1.115/ – 1.135/ – 1.143/ – 1.151/29

45 VSNL ROUTER / / / / / / / / / / / / / / / /29

46 It is reverse (inverse) of Subnetting Combining of Multiple Networks to Single Networks Converting Network Bits to Hosts Bits i.e. Converting 1’s into 0’s Generally design for Class C networks Easier Summarization It is also known as Supernetting CIDR Classless Inter Domain Routing

47 VSNL ROUTER / / / / / / / / / / / / / / / /29

48 Requirement of Hosts is 1000 ? Example – 1 Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Host =2 h – 2  Req. of Host =2 10 – 2  1000 (-2 is for Network ID & Broadcast ID) =1024 – 2 =1022 Hosts/Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

49 Example – 1 (Continued…) Range of Networks Network IDBroadcast ID Customize Subnet Mask = Valid Subnets – – – – – –

50 Requirement of Hosts is ? Example – 2 Class C : N.N.N.H 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx Class C : No. of Host =2 h – 2  Req. of Host =2 14 – 2  (-2 is for Network ID &BroadcastID) =16384 – 2 =16382 Hosts/Subnet 110xxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx HELP

51 Example – 2 (Continued…) Customize Subnet Mask = Range of Networks Network IDBroadcast ID – – – –

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