Networking


  • Home Networking **PLEASE NOTE: This Section is a WORK-IN-PROGRESS** router - modem - switch - port wifi - wired radio lan - wan cellular - 3 vs 4 vs 5ghz phiber vs copper vs


  • CAT5E/6 **PLEASE NOTE: This Section is a WORK-IN-PROGRESS** rj45 - termination a-vs-b etc toning



  • Data **PLEASE NOTE: This Section is a WORK-IN-PROGRESS** Router and Gateway or Default Gateway are all the same thing a router seperates two different networks inside part of router - (wired = 1 mac) outside part of router (the internet = 2nd mac) mac address is hardcoded in hexdecimal- the format is made with 24 bits (6 values) - who made it (the last 24 bits (6 values) = serial number of device. ethernet addressing is mac address DLL (not to be confused with a Dynamic Link Library - which basically function similiarly to java in web design. They contain both code that can be accessed by multiple applications at once as well as links to other resources) a frame is a data link layer component. the data link layer is responsible for local network communication passing information and data in the form of frames through the local network. NLL network interface layer network interface cards - take physical digital signal and convert it into a frame DLL (data link layer) (signal to 1's and zeros to frame) (frame to 1's and zeros to signal) ----------------------------------------------------- mac device "compuer" ip addy device global address subnet mask for separating different local network traffic default gateqay router Data Link Layer Encapsulation in order to move a packet with the ip addresses in it it must be placed inside a frame before it can be sent over a network the frame can only move on the local network it is sent to the router (default gateway) the router discards the frame and places the packet inside a new frame before sending it across the internet this repacking of packets happens each time the packet reaches a router. 255.255.255.0 255.255.255 = network .0 - host network = group of devices host = single device each ip network is unique to the network. a cross over cable allows two computers to communicate with one another (closed non internet network) if you change the ip network of a device it will then be on the network. working example: device one 192.168.104.1 device two 192.168.104.2 non working example: device one 192.168.102.1 device two 192.168.104.2 IPV6 is generally converted on IP4 networks through "network adapters" tunneling. cmd -? ipconfig will show tunneling adapters packet inter net gropper (ping) ping 192.168.104.2 - unreachable reasons "turned off" - "bad ip" "broken ethernet" - "broken router" ipconfig /all - lol (for mac address) which is the same as the physical address you cannot have two devices on the same local network with different global ip addresses that just doesnt work the outside global network is determined by the gateway ip base 10 - numbering system for money, fingers on our hands, etc. (how we count) 0-1-2-3-4-5-6-7-8-9 - deeply engraved in our brains binary - (numbering system for computers, on vs off) 0-1 binary counting 1-2-4-8-16-32-64-128 0 1 01 10 11 100 4s 101 110 111 1000 8s converting binary to decimal 512 256 128 64 32 16 8 4 2 1 1x the place holder and add up all values = decimal. for instance A from ascii is 0100 0001 in binary 128 64 32 16 8 4 2 1 - place 0 1 0 0 0 0 0 1 - binary 'xs the placeholder 0 64 0 0 0 0 0 1 - sum add 64 + 1 = 65 converting decimal to binary can I subtract and end up with 0 or a positive number? 210 128 64 32 16 8 4 2 1 - place can I subtract 128 from 210? y = 82 can I subtract 64 from 82? y = 18 can I subtract 32 from 18? n = can I subtract 16 from 18? y = 2 can I subtract 8 from 2? n = can I subtract 4 from 2? n = can I subtract 2 from 2? y = 0 can I subtract 0 from 0? n = if yes = 1 if no - 0 11010010 = 210 hexadecimal is base 16 every hexadecimal value can always be converted to 4 binary bits (binary is a code of 8 bits or two sets of 4 bits so each hex value when converted to binary is two 4 bit values) 10-11-12-13-14-15 - place 0-1-2-3-4-5-6-7-8-9-A-B-C-D-E-F example: hex 1A5F 1 A 5 F 0001 1010 0101 1111 - binary 8421 8421 8421 8421 - place holder 1 10 5 15 - place value in hexadecimal IP ADDRESSES 203.0.113.10 203.0.113 = network portion - network name .10 = host portion - machine name each number is an octet and each contain 8 bits (4 sets of 8 bits) 203 0 113 10 11001011 00000000 01110001 00001010 (the subnet mask was hacked/add/edited to IPV5 after 1995) it added a separate number to all IP4 addresses which is called the subnet mask it basically adds 1's to network portions and 0 to hosts. 11111111 11111111 1111111 00000000 225 255 255 0 but with current classless IP4 we can change the network portion to any part of our network. you can change the network portion to host portion ration by changing the subnet mask for example you can change the number to 255 200 120 0 which would change the amount of host (the last numbers). understanding pre-1995 ip4 classful ip addressing was split into 4 potions (no subnet mask just the address deciding the ration of net to host) the range is what is determining the portions class A 0.0.0.0 - 127.255.255.255 8bit net 24bit host class B 128.0.0.0 - 191.255.255.255 16 net 16 host class C 192.0.0.0 -223.255.255.255 24bit net - 8 bit host class D 224.0.0.0 - 239.255.255.255 - network portion - this is multi-cast - all network like a bridge What kind of IP address is this? break it into binary and look at the host portion of the ip address network network network host 203 0 113 10 11001011 00000000 01110001 00001010 binary ip addy (look here) 11111111 11111111 1111111 00000000 subnet mask 225 255 255 0 if the host is all binary zeros then it is a network address if it's all 1's in the host portion it is a broadcast IP address and cannot be assigned to any devices. if host is a mix of zeroes and ones it is a host address that can be assigned for example most network ip addresses end in zero but 10.128.224.64 255.255.255.224 - this mask has changed the net to host ratio of the ip 00001010 10000000 11100000 010|00000 - the last 5 are now the host which are all zeros making this a network IP. 11111111 11111111 11111111 111|00000 another example - most host addresses do not end in zero but 10.128.225.0 255.255.254.0 00001010 10000000 1110000|1 00000000 the host portion contains a 1 making this a device/host ip that can be assigned. 11111111 11111111 1111111|0 00000000 ------------------------------------------------------------------------------ private ip ranges (can only be on internal networks) 10.0.0.0 10.255.255.255 172.16.0.0 172.31.255.255 192.168.0.0 192.168.255.255 127.0.0.1 = loop back address or home 01111111.00000000.00000000.00000001 ------------------------------------------------------------------------------- subnet calculator example if 2bits = a network(2 to the number of bits) - each network needs a router unless its a virtual network. for hosts - 2 (if there are 5 bits in the network portion - you can make 32 unique networks) bits networks hosts 0 1 0 1 2 0 2 4 2 3 8 6 - you need 3 bits for 8 networks 4 16 14 - if you need 10 networks you need 4 bits 5 32 30 6 64 62 7 128 126 - 7 bits only gives us 126 hosts 8 256 254 9 512 510 10 1024 1022 11 2048 2046 12 4096 4094 13 8192 8190 this is helpful when deciding how many bits you need in a subnet mask VLSM - Variable Length Subnet Masking basically means different subnet lengths to allow for different hosts amounts as required. so if two subnets need different amount of pcs (available ips) then different subnet numbers should be applied.


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