CCNP Exam Prep Tips and Must Knows


Things You Need to Know about IPv6:

Issues with IPv4

  • Addressing
  • Size of Internet Routing Tables
  • Lack of true end-to-end model

IPv6 Features

  • 128-bit Address Space
  • Elimination of NAT
  • Improved Router Efficiency
  • Broadcast Elimination
  • Transition Richness
  • Mobile IP
  • Improved Security

IPv6 Address Types

  • Unicast
    • Global Unicast Address
    • Link Local Address
  • Multicast
  • Anycast

IPv6 Routing

  • Static Routes
  • RIPng
  • OSPFv3
  • IPv6 EIGRP

IPv6 Route Redistribution

  • RIPng
    • Redistribution between different RIPng processes
    • Redistribution between RIPng and other routing protocols
  • OSPF
    • Redistribution between different OSPF processes
    • Redistribution between OSPF and other routing protocols


  • Redistribution between IGPs and BGP

IPv6 Transition Techniques

  • Dual Stack Techniques
  • IPv4 and IPv6 coexist in the same devices and networks

Tunneling Techniques

  • Manual IPv6 tunnels
    • Simulates a permanent IPv6 link between two IPv6 domains over an IPv4 backbone
    • Tunnel Mode ipv6ip
  • GRE IPv6 Tunnels
    • Simulates a permanent IPv6 link between two IPv6 domains over an IPv4 backbone similar to manual
    • Transport Mechanism is GRE
    • It is the default tunneling protocol on Cisco routers
  • Automatic 6to4 Tunnels
    • Point to Multipoint vs. Point to Point
    • IPv4 addresses are embedded in the IPv6 addresses and are used to find the other tunnel endpoints
    • 2002::/16 is reserved for these
    • Border Routers must be dual-stacked
    • Limited to Static or BGP+4 routing
  • ISATAP Tunnels                     
    • Allows IPv6 only devices to communicate with IPv4-only devices
    • Very similar to other automatic methods, but designed for traffic within a site
    • Uses unicast IPv6 addresses that included a 64 bit prefix and an interface identifier
    • Interface ID created in modified EUI-64 format
    • Uses OUI 00-00-5E-FF in the high order 32 bits of interface ID and the IPv4 tunnel destination add encoded in the low order 32 bits
    • IPv6 64-bit unicast prefix can be any unicast prefix


  • Translates an IPv6 address to an IPv4 address
  • Also translates an IPv4 address to an IPv6 address

Make sure you can configure:

  • IPv6 globally and on an interface
  • IPv6 routing protocol
  • IPv6 Tunnels
  • IPv6 Route Redistribution

Make sure you are familiar with output:

  • sh ipv6 route
  • sh ipv6 interface
  • sh ipv6 ospf neigh
  • sh ipv6 eigrp neighbor
In this article

Join the Conversation