How the Internet Works

How the Internet Works For the Ham DMR FUSION IRLP DSTAR ECHOLINK APRS WINLINK WSPR

Origin of the Internet Began in 1960 when AT&T figured out a way to transfer data over the telephone line Mark and Space tones over the telephone line Because of the military s concern about reliable communications during the cold war, the Defense Advanced Research Agency (DARPA) put out a Request For Proposal (RFP) in 1969 for a communications system which could survive a partial shut down because of a nuclear explosion

Origin of the Internet This DOD communication s system *must* be able to re-route data if some nodes were no longer in the network In the 1970 s, a network grew using Bolt Beranek and Newman s (Inc.) protocol By the end of the 70 s, this protocol was maxed out, since it could only handle 64 Information Message Processors or IMPs

*Last complete logical drawing of the internet

Origin of the Internet 1980, IETF RFC #760, DoD Standard Internet Protocol (IP) was released Based on lessons learned, it revised several features and addressing was now 32 BITS, first 8 is the network part of the address 1981, IETF RFC #791, IP refined, based on more lessons learned; Class A, B, and C network addresses This is the beginning of today's modern internet

Class A Class B Class C Total RFC820 Jan-83 31 24 1042 1097 RFC870 Oct-83 14 37 1834 1885 RFC900 Jun-84 13 53 2398 2464 RFC923 Oct-84 13 69 3209 3291 RFC943 Apr-85 17 77 3551 3645 RFC960 Dec-85 18 91 4721 4829 RFC990 Nov-86 27 154 5800 5981 *They stopped counting and trying to keep track of network addresses after November 1986

Based on the 32 bit IP Address Example: 192.168.1.2 IPv4 Dotted Decimal 1100 0000 1010 1000 0000 0001 0000 0010 Binary Humans read in decimal Computers/routers use binary

LAN vs WAN LAN Local Area Network WAN Wide Area Network (connected LANs) There s a relationship in IP Addressing

IP Address 192.168.1.2 IPv4 Dotted Decimal 1100 0000 1010 1000 0000 0001 0000 0010 Binary The IP addresses had two parts the NETWORK part and the HOST part

IP Address 192.168.1.2 IPv4 Dotted Decimal 1100 0000 1010 1000 0000 0001 0000 0010 Binary In this particular example: the NETWORK part and the HOST part

IP Address Why a NETWORK part and a HOST part? It breaks up the worldwide internet into LANs In most cases, the NETWORK part of the address *is* the LAN address In each LAN, you can connect HOSTs Every host on the internet has a NETWORK address and a HOST address; each HOST has a unique IP address

LAN addresses available for 192.168.1.x 192.168.1.0 -- 1100 0000 1010 1000 0000 0001 0000 0000 192.168.1.1 -- 1100 0000 1010 1000 0000 0001 0000 0001 192.168.1.2 -- 1100 0000 1010 1000 0000 0001 0000 0010 192.168.1.3 -- 1100 0000 1010 1000 0000 0001 0000 0011... 192.168.1.253 -- 1100 0000 1010 1000 0000 0001 1111 1101 192.168.1.254 -- 1100 0000 1010 1000 0000 0001 1111 1110 192.168.1.255 -- 1100 0000 1010 1000 0000 0001 1111 1111 Reserved addresses: Network address: 192.168.1.0 (FIRST ADDRESS) Network broadcast address: 192.168.1.255 (LAST ADDRESS) There s room for 256-2=254 hosts in network 192.168.1.0 192.168.1.1 through 192.168.1.254

Example: 5 LANs connected together NETWORK addresses to form a WAN Internet HOST addresses 192.168.5.3 192.168.1.0 192.168.2.0 192.168.3.0 Hub 192.168.5.0 192.168.4.0 192.168.5.2 192.168.5.1 192.168.4.3 192.168.1.1 192.168.1.2 192.168.1.3 Hub 192.168.2.1 192.168.2.2 192.168.2.3 192.168.3.1 192.168.3.2 192.168.3.3 192.168.4.2 192.168.4.1

Network side and Host side defined by range 192.168.1.2???

Classful Address Ranges Start address - End address 0.0.0.0-127.255.255.255 128.0.0.0-191.255.255.255 192.0.0.0-223.255.255.255 *192.168.1.2 is a Class C Address

IP Address (Classful) Class A Addresses 0.0.0.0 to 127.255.255.255 0000 0000 0000 0000 0000 0000 0000 0000 to 0111 1111 1111 1111 1111 1111 1111 1111 Networks 0-127 2 7 128 Hosts 0-16,777,215 2 24 16,777,216

IP Address (Classful) Class B Addresses 128.0.0.0 to 191.255.255.255 1000 0000 0000 0000 0000 0000 0000 0000 to 1011 1111 1111 1111 1111 1111 1111 1111 Networks 128-191 2 14 16,384 Hosts 0-65,535 2 16 65,536

IP Address (Classful) Class C Addresses 192.0.0.0 to 223.255.255.255 1100 0000 0000 0000 0000 0000 0000 0000 to 1101 1111 1111 1111 1111 1111 1111 1111 Networks 192-223 2 21 2,097,152 Hosts 0-255 2 8 256

IP Address (Classful) Class D Addresses 224.0.0.0 to 239.255.255.255 1110 0000 0000 0000 0000 0000 0000 0000 to 1110 1111 1111 1111 1111 1111 1111 1111 Networks & Hosts undefined Defined use is for multicast

IP Address (Classful) Class E Addresses 240.0.0.0 to 255.255.255.255 1111 0000 0000 0000 0000 0000 0000 0000 to 1111 1111 1111 1111 1111 1111 1111 1111 Networks & Hosts undefined Purpose yet to be defined (Research)

Classful Address Ranges Start address - End address 0.0.0.0-127.255.255.255 128.0.0.0-191.255.255.255 192.0.0.0-223.255.255.255 Turned out to be a very inefficient way to hand out IP addresses! Subnetting (Classless) was the fix.

Classful / Classless IPv4 Addressing Classful addressing turned out to be very inefficient Class C too small for some businesses 2^8 or 254 host addresses Class B too big for most businesses 2^16 or 65,534 host addresses (can't practically implement) Class A network has 2^24 16,777,214 host addresses! Internet Engineering Task Force (IETF) came up with subnetting and Classless Inter-Domain (CIDR) CIDR is a way of aggregating subnet addresses on the internet

IP Address (Classful) Classful Addresses have an implied Subnet Mask Class A Addresses 0.0.0.0 to 127.255.255.255 0000 0000 0000 0000 0000 0000 0000 0000 to 0111 1111 1111 1111 1111 1111 1111 1111 Networks Hosts Implied Subnet Mask 255.0.0.0 1111 1111 0000 0000 0000 0000 0000 0000 Slash Notation: IP Address followed by /8

IP Address (Classful) Classful Addresses have an implied Subnet Mask Class B Addresses 128.0.0.0 to 191.255.255.255 1000 0000 0000 0000 0000 0000 0000 0000 to 1011 1111 1111 1111 1111 1111 1111 1111 Networks Hosts Implied Subnet Mask 255.255.0.0 1111 1111 1111 1111 0000 0000 0000 0000 Slash Notation: IP Address followed by /16

IP Address (Classful) Classful Addresses have an implied Subnet Mask Class C Addresses 192.0.0.0 to 223.255.255.255 1100 0000 0000 0000 0000 0000 0000 0000 to 1101 1111 1111 1111 1111 1111 1111 1111 Networks Hosts Implied Subnet Mask 255.255.255.0 1111 1111 1111 1111 1111 1111 0000 0000 Slash Notation: IP Address followed by /24

IP Address (Classless) Example Subnetted Class A address: Address: 12.7.255.0 0000 1100 0000 0111 1111 1111 0000 0000 Subnet Mask: 255.240.0.0 1111 1111 1111 0000 0000 0000 0000 0000 Networks Subnets Hosts 2 4-2 Subnets available 2 20-2 Hosts available Implied Class A Subnet: Subnet: 1111 1111 0000 0000 0000 0000 0000 0000 255 0 0 0 1111 1111 1111 0000 0000 0000 0000 0000 255 240 0 0 Slash Notation: IP Address followed by /12

IP Address (Classless) Example Subnetted Class B address: Address: 129.32.64.7 1000 0001 0001 0000 0010 0000 0000 0111 Subnet Mask: 255.255.248.0 1111 1111 1111 1111 1111 1000 0000 0000 Networks Hosts Subnets 2 5-2 Subnets available 2 11-2 Hosts available Implied Class B Subnet: Subnet: 1111 1111 1111 1111 0000 0000 0000 0000 255 255 0 0 1111 1111 1111 1111 1111 1000 0000 0000 255 255 248 0 Slash Notation: IP Address followed by /21

IP Address (Classless) Example Subnetted Class C address: Address: 192.168.10.2 1100 0000 1010 1000 0000 1010 0000 0010 Subnet Mask: 255.255.255.224 1111 1111 1111 1111 1111 1111 1110 0000 Networks Hosts Subnets 2 3-2 Subnets available 2 5-2 Hosts available Implied Class C Subnet: Subnet: 1111 1111 1111 1111 1111 1111 0000 0000 255 255 255 0 1111 1111 1111 1111 1111 1111 1110 0000 255 255 255 224 Slash Notation: IP Address followed by /27

IPv4 Addresses 2^32 = 4,294,967,296 Was running out quickly in the 90 s IPv6 was the fix IPv6 is a 128 bit address 2^128 = 3.4 x 10^38 = 340,282,366,920,938,463,463,374,607,431,768,211,456 Roughly equivalent to every grain of sand on Earth Works pretty much the same way as IPv4 This presentation will focus on IPv4 The push toward IPv6 was relieved by NAT NAT = Network Address Translation One PUBLIC address gives you as many PRIVATE addresses as you want

Information is placed on the internet by traversing the TCP/IP Stack 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data 1. Physical Application, software, program, app, such as: frames from: DMR, FUSION, DSTAR, IRLP, ECHOLINK, WINLINK, APRS, etc. MAC IP TCP MTU MAC The Wire or Radio or Fiber Optic TCP or UDP Segment IP Packet MAC Frame (ISO s OSI)

IP Address vs MAC Address In addition to IP Addresses, there are Media Access Control (MAC) Addresses An IP address is virtual you can assign any IP address to any device A MAC Address (AKA Hardware Address ) is hard-wired 48-bit address unique to every device on a LAN Every Network Interface Card (NIC) has a hardwired MAC address that cannot be changed

Information is placed on the internet by traversing the TCP/IP Stack 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data 1. Physical Application, software, program, app, such as: frames from: DMR, FUSION, DSTAR, IRLP, ECHOLINK, WINLINK, APRS, etc. MAC IP TCP MTU MAC The Wire or Radio or Fiber Optic TCP or UDP Segment IP Packet MAC Frame (ISO s OSI)

Where does this MAC address fit in? 1 st, let s start with powering on a There s a lot of things that happen when you first apply power to a One of them is to automatically get enough information to be able to connect to the internet This is done through a protocol called DHCP

DHCP and APIPA Dynamic Host Configuration Protocol (DHCP) Software that automatically and dynamically assigns IP addresses Eliminates the need to manually assign IP addresses Makes it MUCH easier ON by default in today s computers There's DHCP "client" software and There's DHCP server" software

DHCP Four things a computer needs in order to work on a network: IP Address - every host needs a unique IP Address Subnet Mask - defines "network" part of IP Address IP Address to Default Gateway - a way *out* of your LAN" IP Address to DNS - Converts Fully Qualified Domain Name to an IP address

DHCP 1 2 3 4 DHCP Software 1. Client sends DHCP Discover frame 2. sends DHCP Offer frame 3. Client sends DHCP Request frame 4. sends DHCP Acknowledge frame DHCP Client Software gets: IP address Subnet mask IP Address to Default Gateway IP Address to DNS

DHCP ISP DHCP Software DHCP Client Software DHCP Software gets: IP address Subnet mask IP Address to Default Gateway IP Address to DNS 1 2 3 4 DHCP Client Software gets: IP address Subnet mask IP Address to Default Gateway IP Address to DNS

DHCP Software DHCP What if DHCP server is not there, or disconnected or broken for some reason? 1. Client sends DHCP Discover frame 2. Waiting waiting waiting 1 DHCP Client Software gets: waiting waiting waiting

DHCP 1 DHCP Software 1. Client sends DHCP Discover frame 2. Waiting waiting waiting 3. I ve waited long enough -- APIPA DHCP Client Software gets: waiting waiting waiting APIPA

APIPA Automatic Private IP Addressing Protocol implemented soon after DHCP to prevent misleading won t boot symptom If no DHCP server available, assigns itself an APIPA address in the range: 169.254.0.0 to 169.254.255.255 If user says My internet doesn t work, check the IP address (ipconfig) This will instantly tell you there s no DHCP

IP Address vs MAC Address So given a has the following after booting up: IP Address Subnet Mask IP Address to Default Gateway IP Address to DNS - How does a know what MAC address to use? - Another protocol ARP

Address Resolution Protocol (ARP) (Provides a Link between Layer 3 and Layer 2) 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data 1. Physical Application, software, program, app, such as: frames from: DMR, FUSION, DSTAR, IRLP, ECHOLINK, WINLINK, APRS, etc. MAC IP TCP MTU MAC The Wire or Radio or Fiber Optic TCP or UDP Segment IP Packet MAC Frame (ISO s OSI)

Internet 192.168.1.78 192.168.1.65 192.168.1.77 192.168.1.76 192.168.1.75 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000

Internet FE:AA:98:00:00:01 FE:AA:98:00:00:06 FE:AA:98:00:00:02 FE:AA:98:00:00:03 MAC Address FE:AA:98:00:00:04 used from FE:AA:98:00:00:05 device to device IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000

ARP MAC Address used to move data to the next device (next HOP) MAC address of next HOP must be determined for every IP Address IP-to-MAC address mappings are stored in an ARP cache maintained in memory on each device. (When you first power on a, its ARP cache is empty.) If the given IP address does not appear in a device's ARP cache, that device cannot direct messages to that target until it obtains a new mapping and updates its ARP cache To do this, the initiating device sends an ARP request broadcast message on the local subnet (LAN) The host with the given IP address sends an ARP reply in response to the broadcast, allowing the initiating device to update its cache with the correct MAC address The sender can then assemble a MAC Frame and deliver the data to the intended recipient

When you first turn on a, one of the first things to happen is DHCP. DHCP sends out a broadcast looking for a DHCP server, the DHCP server responds and gives the the FOUR THINGS it needs to work on a network. 192.168.1.65 Internet The ARP cache is functionally empty at this point. s ARP Cache IP -Empty MAC 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: Ping 192.168.1.75 Sees this IP address is NOT in the ARP cache Sees this address is in the same subnet Send ARP Broadcast 192.168.1.65 Internet ARP 192.168.1.75? s ARP Cache IP -Empty MAC 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 PING 192.168.1.75 1100 0000 1010 1000 0000 0001 0100 1011

Example: Ping 192.168.1.75 Sees this IP address is NOT in the ARP cache Sees this address is in the same subnet Send ARP Broadcast 192.168.1.77 192.168.1.76 ARP 192.168.1.75? 192.168.1.75 192.168.1.78 ARP 192.168.1.75? ARP 192.168.1.75? ARP 192.168.1.75? 192.168.1.65 ARP 192.168.1.75? s ARP Cache IP -Empty MAC Internet 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 PING 192.168.1.75 1100 0000 1010 1000 0000 0001 0100 1011

Example: Ping 192.168.1.75 Sees this IP address is NOT in the ARP cache Sees this address is in the same subnet Send ARP Broadcast with that IP address recognizes the request 192.168.1.65 Internet! ARP 192.168.1.75? 192.168.1.75 s ARP Cache IP -Empty MAC 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 PING 192.168.1.75 1100 0000 1010 1000 0000 0001 0100 1011

Example: Ping 192.168.1.75 Sees this IP address is NOT in the ARP cache Sees this address is in the same subnet Send ARP Broadcast with that IP address recognizes the request with IP address sends back MAC address 192.168.1.65 Internet Yes, my MAC address is: FFFF EEEE DDDD CCCC 192.168.1.75 s ARP Cache IP -Empty MAC 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 PING 192.168.1.75 1100 0000 1010 1000 0000 0001 0100 1011

Example: Ping 192.168.1.75 Sees this IP address is NOT in the ARP cache Sees this address is in the same subnet Send ARP Broadcast with that IP address recognizes the request with IP address sends back MAC address 192.168.1.65 Internet 192.168.1.75 Yes, my MAC address is: FFFF EEEE DDDD CCCC s ARP Cache IP -Empty MAC 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 PING 192.168.1.75 1100 0000 1010 1000 0000 0001 0100 1011

Example: Ping 192.168.1.75 Sees this IP address is NOT in the ARP cache Sees this address is in the same subnet Send ARP Broadcast with that IP address recognizes the request with IP address sends back MAC address s ARP cache is updated 192.168.1.65 Internet It now knows where to send the Echo Request! 192.168.1.75 s ARP Cache IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 PING 192.168.1.75 1100 0000 1010 1000 0000 0001 0100 1011

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway 192.168.1.65 Internet 192.168.1.75 s ARP Cache IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway 192.168.1.77 192.168.1.76 ARP 192.168.1.65? 192.168.1.75 192.168.1.78 ARP 192.168.1.65? ARP 192.168.1.65? ARP 192.168.1.65? 192.168.1.65 ARP 192.168.1.65? s ARP Cache Internet IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address Yes, my MAC address is: EEEE DDDD CCCC BBBB! 192.168.1.65 Internet s ARP Cache IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address! 192.168.1.65 Internet Yes, my MAC address is: EEEE DDDD CCCC BBBB s ARP Cache IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address ARP Cache is updated! 192.168.1.65 Internet s ARP Cache IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC 192.168.1.65 EEEE DDDD CCCC BBBB - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address ARP Cache is updated Now DSN request can be sent DNS google.com 192.168.1.65 s ARP Cache Internet IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC 192.168.1.65 EEEE DDDD CCCC BBBB - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address ARP Cache is updated Now DSN request can be sent Sends DNS Request to Default Gateway routes based on IP Address 192.168.1.65 DNS google.com Internet s ARP Cache IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC 192.168.1.65 EEEE DDDD CCCC BBBB - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address ARP Cache is updated Now DSN request can be sent Sends DNS Request to Default Gateway routes based on IP Address DNS sends back IP for google 192.168.1.65 s ARP Cache Internet DNS google.com s IP address is 74.125.227.110 IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC 192.168.1.65 EEEE DDDD CCCC BBBB - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address ARP Cache is updated Now DSN request can be sent Sends DNS Request to Default Gateway routes based on IP Address DNS sends back IP for google DNS cache updated Since Address to google is not in the same subnet, it knows to send HTTP request to default gateway then routes on IP 192.168.1.65 s DNS Cache Domain IP Google.com 74.125.227.110 - s ARP Cache Internet IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC 192.168.1.65 EEEE DDDD CCCC BBBB - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 Address to Google 74.125.227.110 0100 1010 0111 1101 1110 0011 0110 1110

Example: www.google.com Need DNS Sees DNS is NOT in the same subnet Sends out ARP request for Default Gateway Default Gateway responds with MAC Address ARP Cache is updated Now DSN request can be sent Sends DNS Request to Default Gateway routes based on IP Address DNS sends back IP for google DNS cache updated Since Address to google is not in the same subnet, it knows to send HTTP request to default gateway then routes on IP 192.168.1.65 s DNS Cache s ARP Cache Internet http://www.google.com Domain IP Google.com 74.125.227.110 - IP MAC 192.168.1.75 FFFF EEEE DDDD CCCC 192.168.1.65 EEEE DDDD CCCC BBBB - 192.168.1.74 IP Address 192.168.1.74 1100 0000 1010 1000 0000 0001 0100 1010 Subnet Mask 255.255.255.192 1111 1111 1111 1111 1111 1111 1100 0000 Default Gateway 192.168.1.65 1100 0000 1010 1000 0000 0001 0100 0001 Address to DNS 206.255.244.169 1100 1101 1111 1111 1111 0100 1010 1001 Address to Google 74.125.227.110 0100 1010 0111 1101 1110 0011 0110 1110

ARP View ARP cache: c:\arp a (-a = view all) View DNS cache: c:\ipconfig /displaydns

Information is placed on the internet by traversing the TCP/IP Stack 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data 1. Physical Application, software, program, app, such as: frames from: DMR, FUSION, DSTAR, IRLP, ECHOLINK, WINLINK, APRS, etc. MAC IP TCP MTU MAC The Wire or Radio or Fiber Optic TCP or UDP Segment IP Packet MAC Frame (ISO s OSI)

Email Example Application Presentation Session Transport Network Data Physical Example: Email From: userhere@someplace.com To: userthere@someotherplace.com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me is actually a text file From: userhere@someplace.com To: userthere@someotherplace.com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me That gets broken up in to chunks (MTUs) From: userhere @someplace.com To: userthere@ someotherplace. com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me

Email Example Application Presentation Session Transport Network Data Physical From: userhere TCP Header From: userhere In this case (Email) TCP is used vs UDP SEGMENT TCP Header/Trailer information: Source port (Port Number explained later) Destination port Sequence Acknowledgement and some other stuff

Email Example Application Presentation Session Transport Network Data Physical From: userhere TCP Header From: userhere IP Header TCP Header From: userhere IP address usually obtained through DNS SEGMENT PACKET IP Header/Trailer information: Source IP address Destination IP address Length Protocol Time to live And some other stuff

Email Example Application Presentation Session Transport Network Data Physical IP Header TCP Header TCP Header From: userhere From: userhere From: userhere SEGMENT PACKET FRAME MAC Header IP Header TCP Header From: userhere MAC Trailer MAC Address Hardwired and used to transmit from device to device MAC Header/Trailer information: Source address Destination address CRC and some other stuff

Email Example Application Presentation Session Transport Network Data Physical IP Header TCP Header TCP Header From: userhere From: userhere From: userhere SEGMENT PACKET FRAME MAC Header IP Header TCP Header From: userhere MAC Trailer

Email Example Application Presentation Session Transport Network Data Physical IP Header TCP Header TCP Header From: userhere From: userhere From: userhere SEGMENT PACKET FRAME MAC Header IP Header TCP Header From: userhere MAC Trailer Host or Network Device NIC Wire NIC Host or Network Device Host or Network Device NIC Host or Network Device NIC NIC Host or Network Device

Can Encapsulate just about anything! MAC IP UDP MAC MAC IP UDP MAC MAC IP UDP DMR MAC (max MTU size 1500 bytes)

Email Example Data Segment Packet Frame Internet 192.168.3.0 to - examines MAC -Determines which way to forward -Sends 192.168.1.0 192.168.2.0 Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Data Segment Packet Frame 192.168.1.0 192.168.2.0 Internet 192.168.3.0 to - strips away MAC -Examines IP -Determines which way to forward -Builds new MAC -Sends Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Data Segment Packet Frame 192.168.1.0 192.168.2.0 Internet 192.168.3.0 to - strips away MAC -Examines IP -Determines which way to forward -Builds new MAC -Sends Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Data Segment Packet Frame Internet 192.168.3.0 to - examines MAC -Determines which way to forward -Sends 192.168.1.0 192.168.2.0 Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Data Segment Packet Frame 192.168.1.0 192.168.2.0 Hub File 192.168.3.1 Internet 192.168.3.0 Email 192.168.3.2 Web to Email -Email strips away MAC -Examines IP - Sees it s MINE! -Strips away IP Header -Examines TCP Header -Determines an Acknowledgement is required and sends it back 192.168.3.3 -Strips away TCP Header, stores first part of data and waits for further data to assemble 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.3.0 192.168.1.0 192.168.2.0 1From: userhere Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.3.0 192.168.1.0 192.168.2.0 1From: userhere 2@someplace.com Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.3.0 192.168.1.0 192.168.2.0 1From: userhere 3To: userthere@ 2@someplace.com Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.3.0 192.168.1.0 192.168.2.0 2@someplace.com 1From: userhere 4someotherplace. 3To: userthere@ Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.3.0 3To: userthere@ 2@someplace.com 192.168.1.0 192.168.2.0 Hub 5com Subject: 4someotherplace. File 192.168.3.1 1From: userhere Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.3.0 3To: userthere@ 192.168.1.0 192.168.2.0 5com Subject: Hub 6Test email Dear 4someotherplace. File 192.168.3.1 2@someplace.com Email 192.168.3.2 Web 1 ACK 192.168.3.3 1From: userhere 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 5com Subject: 192.168.3.0 4someotherplace. 1 ACK 192.168.1.0 192.168.2.0 Hub 7user over there, 6Test email Dear File 192.168.3.1 3To: userthere@ Email 192.168.3.2 Web 2 ACK 192.168.3.3 1From: userhere 2@someplace.com 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 1 ACK 6Test email Dear 192.168.1.0 192.168.2.0 192.168.3.0 2 ACK 5com Subject: 4someotherplace. 3 ACK 1From: userhere 2@someplace.com 3To: userthere@ 8this is a test 7user over there, Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 1 ACK 2 ACK 192.168.1.0 192.168.2.0 8this is a test 9email. Thanks 7user over there, Hub File 192.168.3.1 192.168.3.0 3 ACK 6Test email Dear 5com Subject: Email 192.168.3.2 Web 4 ACK 192.168.3.3 1From: userhere 2@someplace.com 3To: userthere@ 4someotherplace. 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 1From: userhere 2@someplace.com 3To: userthere@ Internet 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 3 ACK 192.168.3.0 7user over there, 4 ACK 1From: userhere 192.168.1.0 192.168.2.0 2 ACK Hub 10for listening. 9email. Thanks 8this is a test File 192.168.3.1 6Test email Dear Email 192.168.3.2 Web 5 ACK 192.168.3.3 2@someplace.com 3To: userthere@ 4someotherplace. 5com Subject: 1 ACK 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 4someotherplace. 2@someplace.com 5com Subject: 3To: userthere@ 6Test email Dear Internet 1From: userhere 2@someplace.com 7user over there, 8this is a test 9email. Thanks 3To: userthere@ 10for listening. 11Sincerely, Me 4 ACK 192.168.3.0 8this is a test 5 ACK 4someotherplace. 5com Subject: 192.168.1.0 192.168.2.0 3 ACK Hub 11Sincerely, Me 10for listening. 9email. Thanks File 192.168.3.1 7user over there, Email 192.168.3.2 Web 6 ACK 192.168.3.3 6Test email Dear 2 ACK 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 4someotherplace. 5com Subject: 3To: userthere@ 6Test email Dear Internet 1From: userhere 2@someplace.com 7user over there, 8this is a test 9email. Thanks 3To: userthere@ 10for listening. 11Sincerely, Me 5 ACK 192.168.3.0 6 ACK 9email. Thanks 4someotherplace. 5com Subject: 192.168.1.0 192.168.2.0 4 ACK 11Sincerely, Me Hub 3 ACK 10for listening. File 192.168.3.1 8this is a test Email 192.168.3.2 Web 7 ACK 192.168.3.3 6Test email Dear 7user over there, 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 4someotherplace. 5com Subject: 6Test email Dear Internet 1From: userhere 2@someplace.com 7user over there, 8this is a test 9email. Thanks 3To: userthere@ 10for listening. 11Sincerely, Me 6 ACK 192.168.3.0 10for listening. 7 ACK 4someotherplace. 5com Subject: 192.168.1.0 192.168.2.0 5 ACK Hub 4 ACK 11Sincerely, Me File 192.168.3.1 9email. Thanks Email 192.168.3.2 Web 8 ACK 192.168.3.3 6Test email Dear 7user over there, 8this is a test 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 7 ACK 192.168.1.0 192.168.2.0 6 ACK Hub 5 ACK File 192.168.3.1 Internet 192.168.3.0 11Sincerely, Me 10for listening. Email 192.168.3.2 Web 8 ACK 9 ACK 192.168.3.3 1From: userhere 2@someplace.com 3To: userthere@ 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 7 ACK Hub 6 ACK 192.168.3.0 9 ACK 8 ACK 192.168.1.0 192.168.2.0 File 192.168.3.1 Internet Email 192.168.3.2 11Sincerely, Me Web 10 ACK 192.168.3.3 1From: userhere 2@someplace.com 3To: userthere@ 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 8 ACK 7 ACK Hub 192.168.3.0 10 ACK 9 ACK 192.168.1.0 192.168.2.0 File 192.168.3.1 Internet 11 ACK Email 192.168.3.2 Web 192.168.3.3 1From: userhere 2@someplace.com 3To: userthere@ 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Internet 1From: userhere 2@someplace.com 10for listening. 8this is a test 9email. Thanks 11Sincerely, Me 192.168.3.0 11 ACK 10 ACK 192.168.1.0 192.168.2.0 9 ACK 8 ACK Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 3To: userthere@ 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Internet 1From: userhere 2@someplace.com 10for listening. 11Sincerely, Me 9email. Thanks 11 ACK 192.168.1.0 192.168.2.0 10 ACK 9 ACK Hub File 192.168.3.1 192.168.3.0 Email 192.168.3.2 Web 192.168.3.3 3To: userthere@ 4someotherplace. 5com Subject: 6Test email Dear 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Internet 1From: userhere 2@someplace.com 3To: userthere@ 10for listening. 11Sincerely, Me 192.168.3.0 4someotherplace. 5com Subject: 192.168.1.0 192.168.2.0 6Test email Dear 7user over there, 11 ACK 10 ACK Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Internet 1From: userhere 2@someplace.com 3To: userthere@ 11Sincerely, Me 192.168.3.0 4someotherplace. 5com Subject: 192.168.1.0 192.168.2.0 6Test email Dear 7user over there, 11 ACK Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Internet 1From: userhere 2@someplace.com 3To: userthere@ 192.168.3.0 4someotherplace. 5com Subject: 192.168.1.0 192.168.2.0 6Test email Dear 7user over there, Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Internet All info now at Email 1From: userhere 192.168.3.0 2@someplace.com 3To: userthere@ 4someotherplace. 192.168.1.0 192.168.2.0 5com Subject: 6Test email Dear Hub File 192.168.3.1 Email 192.168.3.2 Web 192.168.3.3 7user over there, 8this is a test 9email. Thanks 10for listening. 11Sincerely, Me 192.168.1.1 192.168.1.2 192.168.1.3 192.168.2.1 192.168.2.2 192.168.2.3

Email Example Application Presentation Session Transport Network Data Physical From: userhere @someplace.com To: userthere@ someotherplace. com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me Chunks (MTUs) then reassembled into a text file From: userhere@someplace.com To: userthere@someotherplace.com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me

Email Example Application Presentation Session Transport Network Data Physical From: userhere @someplace.com To: userthere@ someotherplace. com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me Chunks (MTUs) then reassembled into a text file From: userhere@someplace.com To: userthere@someotherplace.com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me Application then displays it as an Email From: userhere@someplace.com To: userthere@someotherplace.com Subject: Test email Dear user over there, this is a test email. Thanks for listening. Sincerely, Me

Just about anything can be encapsulated by an IP Packet 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data 1. Physical Application, software, program, app, such as: frames from: DMR, FUSION, DSTAR, IRLP, ECHOLINK, WINLINK, APRS, etc. MAC IP TCP MTU MAC The Wire or Radio or Fiber Optic TCP or UDP Segment IP Packet MAC Frame (ISO s OSI)

ISO s OSI TCP/IP ISO s OSI 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data 1 Physical Applications such as: HTTP, SMTP, DSTAR, FUSION, DMR, IRLP, ECHOLINK, APRS, etc. 99.9% of the time, TCP or UDP 99.9% of the time, IP Examples: IEEE 802.3, IEEE 802.11 (MAC) Examples: Ethernet, USB, Serial Connectors Air Interface, etc.

You are located some where in the BLUE! Internet Logical Map 2015 - http://www.opte.org/

How the Internet Works For the Ham DMR FUSION IRLP DSTAR ECHOLINK APRS WINLINK WSPR