Network layer

Network layer

1. configuration of a Cisco router

   • initial parameters
     • switch configuration
       • similarity routers and cisco switches
     • Router configuration
   • interface configuration
     • Configure router interfaces
   • pre-determined gateway
     • Default gateway for a host
       • The default gateway is used only when the host wants to send a packet to a device on another network
     • Default gateway for a switch
       • is configured on all devices that want to communicate beyond the local network

2. routers

   • anatomy of a router
     • A router is a computer.
       • From branch
       • WAN
       • Service provider
     • The CPU and the router OS
       • The CPU needs an OS to provide the routing and switching functions
     • Router memory
       • RAM
       • ROM
       • VRAM
       • Fladh
     • Interior of a router
     • Connection to a router
       • Cisco switches, routers and devices interconnect many devices
     • WAN and LAN interfaces
       • Console
       • Secure Shell (SSH)
       • Telnet
   • router start
     • Bootset files
       • is modified when the network administrator performs device configurations
     • Process of starting the router
       • Realization of the POST and loading of the boot program
       • the IOS is stored in flash memory and copied into RAM for the CPU to run

3. network layer protocols

   • the network layer in communications
     • The network layer
       • Addressing terminals
       • Encapsulation
       • Routing
       • Decapsulation
     • Network layer protocols
       • Internet Protocol version 4
       • Internet Protocol version 6
   • IP protocol characteristics
     • Encapsulamiento de IP
     • IP characteristics
       • IP was designed as a protocol with low overhead
     • IP: Offline
       • Offline data communications work with the same principle
     • IP: Minimum service delivery
       • IP does not have the functionality to manage or recover packages that are not received or damaged
     • IP: Independent of the media
       • prepare IP packets for transmission by the communication medium
   • IPv4 package
     • IPv4 packet header
   • IPv6 package
     • IPv4 limitations
       • Exhaustion of IP addresses
       • Expansion of the Internet routing table
       • Lack of complete connectivity
     • IPv6 encapsulation
       • A lot of advantages
     • IPv6 packet header

4. routing

   • How do you route the host routes?
     • The decision of host forwarding
     • Default gateway
       • The default gateway is like the door.
     • Use of the default gateway
       • dynamic way of the DHCP protocol or if it is configured manually
   • Router routing tables
     • Decision to send router packets
       • Routes connected directly
       • Remote routes
       • Default route
     • IPv4 router routing table
     • Directly connected routing table entries
     • Routing table entries of remote networks
     • Direction of the next jump