CCNA Notes

200-301 Exam Prep

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1Networking Devices2Interfaces And Cables3OSI Model and TCP/IP Suite4Intro to the CLI5Ethernet LAN Switching - Part 16Ethernet LAN Switching - Part 27IPv4 Addressing - Part 18IPv4 Addressing - Part 29Switch Interfaces10The IPv4 Header11Routing Fundamentals - Part 111Static Routing - Part 212Life of a Packet13Subnetting - Part 114Subnetting - Part 215Subnetting (VLSM) - Part 316VLANs - Part 117VLANs - Part 218VLANs - Part 319DTP / VTP20Spanning Tree Protocol - Part 121Spanning Tree Protocol - Part 222Rapid Spanning Tree Protocol23Etherchannel24Dynamic Routing25RIP / EIGRP26OSPF - Part 127OSPF - Part 228OSPF - Part 329First Hop Redundancy Protocol30TCP and UDP31IPv6 - Part 132IPv6 - Part 233IPv6 - Part 334Standard Access Control List35Extended Access Control List36CDP and LLDP37NTP - Network Time Protocol38DNS - Domain Name System39DHCP - Dynamic Host Configuration Protocol40SNMP - Simple Network Management Protocol41SYSLOG42SSH - Secure Shell43FTP and TFTP44NAT (Static) - Part 145NAT (Dynamic) - Part 246QoS (Voice VLAN) - Part 147QoS (Quality of Service) - Part 248Security Fundamentals49Port Security50DHCP Snooping51Dynamic ARP Inspection52LAN Architectures53WAN Architectures54Virtualization and Cloud - Part 154Virtualization (Containers) - Part 254Virtualization (VRF) - Part 355Wireless Fundamentals56Wireless Architectures57Wireless Security58Wireless Configuration59Introduction to Network Automation60JSON, XML, and YAML61REST APIs62Software Defined Networking63Ansible, Puppet, and Chef67CCNA Complete Cheatsheet
/Routing Fundamentals - Part 1
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Routing Fundamentals - Part 1

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11. ROUTING FUNDAMENTALS : PART 1

WHAT IS ROUTING ?

ROUTING is the process that routers use to determine the path that IP packets should take over a network to reach their destination.

  • ROUTERS store routes to all their known destinations in a ROUTING TABLE
  • When ROUTERS receive PACKETS, they look in the ROUTING TABLE to find the best route to forward that packet.

There are two main routing methods (methods that routers use to learn routes):

  • DYNAMIC ROUTING : ROUTERS use Dynamic Routing Protocols (ie: OSPF) to share routing information with each other automatically and build their routing tables.
  • STATIC ROUTING : A network engineer / Admin manually configures routes on the router.

A ROUTE tells the ROUTER :

  • to send a packet to Destination X, you should send the pack to next-hop Y
  • or if the Destination is directly connected to the router, send the packet directly to the destination.
  • or if the Destination is the router’s own IP address, receive the packet for yourself (don’t forward it).

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WAN (Wide Area Network) = network that extends over a large geographic area.

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