Routing Table and CDP Protocol

Routing Table and CDP Protocol

 Purpose of the debug ip routing command
– Allows you to view changes that the router performs when
   adding or removing routes.
– Example:
• R2#debug ip routing
• IP routing debugging is on

To configure an Ethernet interface

– Example:
• R2(config)#interface fastethernet 0/0
• R2(config-if)#ip address 172.16.1.1 255.255.255.0
• R2(config-if)#no shutdown

 

•  Routing Table and CDP Protocol Checking each

When a router only has its interfaces configured & no
   other routing protocols are configured then:
– The routing table contains only the directly connected networks
– Only devices on the directly connected networks are reachable

• Routing Table and CDP Protocol Checking each

Route in turn
– The ping
    command is
    used to check
    end to end
    connectivity

•  Purpose of CDP

– A layer 2 cisco proprietary tool used to gather information
   about other directly connected Cisco devices.

•  Concept of neighbors

– 2 types of neighbors:
  • Layer 3 neighbors
  • Layer 2 neighbors

•   CDP show commands

– Show cdp neighbors command
    • Displays the following information:
– Neighbor device ID
– Local interface
– Holdtime value, in seconds
– Neighbor device capability code
– Neighbor hardware platform
– Neighbor remote port ID
– Show cdp neighbors detail command
    • Useful in determining if an IP address configuration error

•  Disabling CDP

– To disable CDP globally use the following command
    • Router(config)#no cdp run

file packet tracker download