Foundation Summary

The Foundation Summary provides a convenient review of many key concepts in this chapter. If you are already comfortable with the topics in this chapter, this summary might help you recall a few details. If you just read this chapter, this review should help solidify some key facts. If you are doing your final prep before the exam, the following lists, tables, and figures are a convenient way to review the day before the exam.

IPv6 supports the following routing methods:

  • Static routes

  • RIPng

  • EIGRP for IPv6

  • IS-IS for IPv6

  • MP-BGP4

  • OSPFv3

OSPFv3 shares the following features with OSPFv2:

  • Link-state (uses SPF algorithm, areas, hellos, LSAs, DBDs, and LSDB)

  • Packet types, method to form neighbor relationships, and NBMA topology support

  • Stub area support

OSPFv3 is different from OSPFv2 in many ways, including the following:

  • Has 128-bit prefix support and runs within IPv6 packets; however, still uses 32-bit router ID, area ID, and link-state ID

  • Uses multicast addresses FF02::5 and FF02::6

  • Uses links rather than subnets; uses link-local address as source address

  • Has a 16-byte packet header; authentication not built-in, uses IPv6 extension headers instead

  • Has support for multiple instances

OSPFv3 LSA types 1 and 2 no longer contain route prefixes, instead they contain 32-bit IDs. Types 3 and 4 have been renamed but still fulfill the same functions as they do in OSPFv2. Types 8 and 9 are new LSAs in OSPFv3.

Table 21-3 summarizes the IPv6 and OPSFv3 configuration commands covered in this chapter.

Table 21-3. IPv6 and OSPFv3 Configuration Commands Covered in This Chapter
Router(config)# ipv6 route ipv6-prefix/prefix-length {ipv6-address | interface-type interface-number [ipv6-address]} [administrative-distance] [administrative-multicast-distance | unicast | multicast] [next-hop-address] [tag tag]Creates an IPv6 static route.
Router(config)#ipv6 unicast-routingEnables IPv6.
Router(config)#ipv6 cefEnables CEFv6.
Router(config-if)#ipv6 address ipv6-prefix/prefix-length [eui-64]Assigns an IPv6 address to an interface.
Router(config)#ipv6 router ospf process-idCreates an OSPFv3 process.
Router(config-rtr)#router-id 32-bit-router-idAssigns a 32-bit router ID, in an IPv4-address dotted decimal format.
Router(config-rtr)#area area-id range summary-range/prefix-length [advertise | not-advertise] [cost cost]Summarizes an area into another area.
Router(config-if)#ipv6 ospf process-id area area-id [instance instance-id]Assigns an interface to an OSPFv3 area.
Router(config-if)#ipv6 ospf priority priorityChanges the OSPF priority from its default of 1.
Router(config-if)#ipv6 ospf cost interface-costChanges the OSPF default cost.

Table 21-4 summarizes the IPv6 and OPSFv3 verification commands covered in this chapter.

Table 21-4. IPv6 and OSPFv3 Verification Commands Covered in This Chapter
show ipv6 routeDisplays the IPv6 routing table.
ping [ipv6] ipv6-addressPings an IPv6 address.
clear ipv6 ospf [process-id] {process | force-spf | redistribution | counters [neighbor [neighbor-interface | neighbor-id]]}Triggers SPF recalculation and repopulation of the routing table.
show ipv6 interface [brief] [interface-type interface-number] [prefix]Displays IPv6 information about an interface.
show ipv6 ospf interfaceDisplays interface-specific OSPFv3 information.
show ipv6 ospfDisplays the OSPFv3 router ID and timers, as well as other general routing protocol settings.
show ipv6 ospf neighbor [detail]Displays OSPFv3 neighbor information.
show ipv6 ospf database [database-summary]Displays OSPFv3 database.

There are several transition mechanisms from IPv4 to IPv6:

  • Dual Stack— Dual stack simply means to run IPv6 and IPv4 concurrently, with no communication between the two.

  • Tunneling— With tunneling, routers that straddle the IPv4 and IPv6 worlds encapsulate the IPv6 traffic inside IPv4 packets. Four types of tunneling are described in this chapter: manual, 6-to-4, ISATAP, and Teredo.

  • Translation— Translation allows IPv6 devices to communicate with IPv4 devices, without requiring either to be dual stack. SIIT translates IP header fields, and NAT-PT maps IPv6 addresses to IPv4 addresses.