NETWORK LAYER

NETWORK LAYER

1. Network layer protocols

   • The network layer in communications
     • The network layer
       • services to allow terminals to exchange data
     • Network layer protocols
       • Internet Protocol version 4 (IPv4)
       • Internet Protocol version 6 (IPv6)
   • Characteristics of the IP protocol
     • IP encapsulation
       • the transport layer segment or other data, IP adds an IP header.
     • IP characteristics
       • functions necessary to send a packet from an origin to a destination through an interconnected.
     • IP: Offline
       • sending a letter to someone without notifying the recipient
     • IP: Minimum service delivery
       • not guarantee that all packages that are sent, in fact,
     • IP: Independent of the media
       • the media that carries the data in the lower layers
   • IPv4 package
     • IPv4 packet header
       • fields that contain important information
   • IPv6 package
     • Limitations of IPv4
       • Exhaustion of IP addresses
       • Expansion of the Internet routing table
       • Lack of complete connectivity
     • Introduction to IPv6
       • Ilimitations of IPv6 and represents a major improvement with features that better adapt
     • IPv6 encapsulation
       • important design improvements of IPv6 with respect to IPv6 header.

2. Routers

   • Router anatomy
     • A router is a computer
       • function, size or complexity, all router models are, in essence
     • The CPU and the OS of the router
       • execute OS instructions, such as system initialization, routing and switching
     • Router memory
       • access to a volatile and non-volatile memory .
     • Interior of a router
       • router, such as the power supply, the fan, the thermal screens and an advanced
     • Connection to a router
       • switches, routers and Cisco devices interconnect
   • Starting the router
     • Bootset files
       • the startup configuration file into the RAM
     • Process of starting the router
       • POST and loading of the boot program
       • Location and loading
       • loading of the configuration file
     • Result of show version
       • the Cisco IOS software version that is currently running

3. Configuring a cisco router

   • Configuration of the initial parameters
     • many similarities. They support a similar operating system, similar command structures and many
   • Basic steps in configuring a router
     • configured, when initial parameters are configured on a router, tasks must
   • Interface configuration
     • Configure router interfaces
       • the routers, the in-band router interfaces
     • Verification of interface configuration
       • show ip interface brief. The generated result shows all the interfaces, their IPv4 address
   • Default gateway configuration
     • Default gateway for a host
       • ommunicate over the network, it must be configured with the correct IP address information,
     • Default gateway for a switch
       • switch that interconnects client computers

4. Routing

   • How weapons routes the host
     • The decision of host forwarding
       • function of the network layer is to direct packets
     • Default gateway
       • device that can route traffic to other networks
     • Use of the default gateway
       • host usually includes a default gateway.
   • Routing router tables
     • Decision to send router packets
       • packet to another, it uses its routing table
     • IPv4 router routing table
       • show ip route command to display the router's IPv4
     • Routing table entries connected directly
       • router interface with an IPv4 address, a subnet mask
     • Routing table entries of remote networks
       • several interfaces configured. The routing table stores information about directly connected .
     • Direction of the next jump
       • the router sends the packet to the next hop address of the identified .