1. Diagnostics
   1. Cisco four step solutuon
      1. Ping loopback address 127.0.0.1
         1. Success: NIC AIO
         2. Failure: NIC faulty
      2. Ping Host IP
         1. Success: TCP stack initialised
         2. Failure: TCP stack faulty
      3. Ping gateway
         1. Success: connected to network
         2. Failure: Physical problem from NIC to router
      4. Ping remote device
         1. Success: Remote Network AIO
         2. Failure: remote server problem
2. Subnetting
   1. Basics
      1. Take on large network and segment into smaller networks
         1. Benefits
            1. Reduced Network Traffic
            2. Optimised network performance
            3. Siplified management
            4. Easily span large distances
         2. Subentting technique
            1. Determine number of required Network ID's
            2. One for each subnet
            3. One for each WAN connection
            4. Determine amount of hosts/subenett
            5. One for each TCP/IP host
            6. One for each router interface
            7. Based on above create:
            8. one sumnet mask for your entire network
            9. a unique subnet ID for each physical segment
            10. A range of host ID's for each segment
      2. How to subnet
         1. 2^X= # subnets. X= masked bits (1's)
         2. 2^y-2= #Hosts/subnet. y=unmasked bits (o's)
         3. 256-subnet mask=block size
         4. Broadcast address=number before next subnet
         5. valid host range=numbers inbetween network and b'cast
   2. Masks
      1. Class A mask
         1. 255.0.0.0
      2. Class B mask
         1. 255.255.0.0
      3. Class C mask
         1. 255.255.255.0
   3. CIDR
      1. used instead of decimal notation
      2. used as slash notation after IP address
         1. EG: 192.168.0.0/28
      3. CIDR Table
         1. CIDR Table
            1. 255.0.0.0
            2. 255.128.0.0
            3. 255.192.0.0
            4. 255.224.0.0
            5. 255.240.0.0
            6. 255.248.0.0
            7. 255.252.0.0
            8. 255.254.0.0
            9. 255.255.0.0
            10. 255.255.128.0
            11. 255.255.192.0
            12. 255.255.224.0
            13. 255.255.240.0
            14. 255.255.248.0
            15. 255.255.252.0
            16. 55.255.254.0.
            17. 255.255.255.0
            18. 255.255.255.128
            19. 255.255.255.192
            20. 255.255.255.224
            21. 255.255.255.240
            22. 255.255.255.248
            23. 255.255.255.252
            24. /8
            25. /9
            26. /10
            27. /11
            28. /12
            29. /13
            30. /14
            31. /15
            32. /16
            33. /17
            34. /18
            35. /19
            36. /20
            37. /21
            38. /22
            39. /23
            40. /24
            41. /25
            42. /26
            43. /27
            44. /28
            45. /29
            46. /30
            47. 1
            48. 128
            49. 64
            50. 32
            51. 16
            52. 8
            53. 4
            54. 2
            55. 1
            56. 128
            57. 64
            58. 32
            59. 16
            60. 8
            61. 4
            62. 2
            63. 1
            64. 128
            65. 64
            66. 32
            67. 16
            68. 8
            69. 4
   4. Subnet in your head
      1. work out block size (256-mask)
         1. EG: 192.168.0.24/26
         2. 256-192=64
      2. Count up networks
         1. 0, 64, 128...
      3. determine broadcast address
         1. broadcast of 0=63
3. Summarisation
   1. AKA route Aggregation or Supernetting
   2. Used to keep smaller Routing tables
   3. Supernet as follows
      1. How many addresses in range?
         1. EG: 192.168.0.0-192.168.3.0 range 4
      2. What power of 2 gives our range?
         1. 2^2=4
      3. Subtract answer from 2 from default mask of address range
         1. /24-2=/22
      4. add this to first address in range
         1. 192.168.0.0/22
4. Troubleshooting
   1. Ping NIC 127.0.0.1
   2. Tracert
      1. tracks path of packet through network
      2. Cisco equivalent: Traceroute or Trace
   3. ipconfig/all
      1. PC network configuration
   4. arp -a
      1. Lists IP to MAC resolution
      2. Cisco Equivalent: show ip arp
   5. Check IP address allocation is correct
5. VLSM's
   1. used to make subnets of different sizes
   2. Classful routing protocols
      1. RIP
      2. IGRP
      3. Inefficient
   3. Classless routing protocols
      1. RIPv2
      2. EIGRP
      3. OSPF
      4. Efficient
   4. Use block sizes to work out hosts to implement