Chap 10 - OSPFv3 Flashcards
What are 9 ways that OSPFv3 is different from OSPFv2?
- Multiple Address Families
- New LSA types
- Removal of Address Semantics from OSPF packet headers
- LSA Flooding scope is identified
- Packet format - number of fields has been reduced
- Router ID - must be manually assigned
- Authentication - removed from OSPFv3
- Neighbor adjacencies - handled by link-local addressing
- Multiple Instances - OSPFv3 packets carry Instance ID
What are the 8 LSA Types in OSPFv3?
- 0x2001 Router
- 0x2002 Network
- 0x2003 InterArea Prefix
- 0x2004 InterArea Router
- 0x4005 AS External
- 0x2007 NSSA
- 0x0008 Link
- 0x2009 IntraArea Prefix
In the LSA types what is the difference between 0x2 , 0x0 , and 0x4 ?
- 0x0 - LSA scope limited to the link itself
- 0x2 - LSA stays within the area
- 0x4 - LSA is flooded throughout the entire AS
What address does the DR and BDR use to communicate with the DROthers?
FF02::05
What address does the DROthers use to communicate with the DR and BDR?
FF02::06
What are the 5 packet types used by OSPFv3?
- Hello
- DD
- LSR
- LSU
- Link-state Ack
In terms of Router ID what happens if there are no IPv4 interface addresses configured on the router?
OSPFv3 sets the router ID to 0.0.0.0 and no adjacencies will be allowed to be formed.
What is different about the ‘router’ command in OSPFv3?
It is now ‘router ospfv3 (process_id)
What is different about the ‘show interface’ command?
- It is now ‘show ospfv3 interface gig0/1’
- It no longer shows an IP address, just an Interface ID
What is new in OSPFv3 about address families?
OSPFv3 now supports both IPv4 and IPv6
What is different about IP addresses in OSPFv3?
IP addresses are no longer in the OSPFv3 packet headers. Instead its part of the payload in the LSAs.
What is the term for network in OSPFv3?
Link because the SPF calculations are per link instead of per subnet.
What is new in OSPFv3 about LSA Flooding?
OSPFv3 includes a Link-state Type field used to determine the flooding scope as well as handling of unknown LSA types.
Can 2 routers be OSPF neighbors even if they don’t share a common subnet?
Yes
What protocol ID does OSPFv3 use?
89
True or False - In OSPFv3 a routing process does not need to be specifically created.
True. Enabling OSPFv3 on an interface will create the associated routing process.
When do you need to manually configure neighbors?
On NBMA networks.
What does a Type 0x2001 Router LSA do?
- Describes link state and costs of a router’s links to the area.
- Flooded within the area only.
- Indicates if router is a ABR or ASBR
- Contains no address information
- Network protocol independent
What does a Type 0x2002 Network LSA do?
- Describes link state and cost info for all routers attached to the network
- Aggregates all the link state and cost information in the network
- Generated only by the DR
- Contains no address info
- Network protocol independent
What does a Type 0x2003 InterArea Prefix LSA do?
- Advertises internal networks to routers in other areas (InterArea Routes)
- May represent a single network or a summary
- Only ABRs generate these
- Addresses expressed as prefix and prefix length
- Default route expressed as prefix with prefix length of 0
What does a Type 0x2004 InterArea Router LSA do?
- Advertises the location of ASBRs
- Generated by ABRs on behalf of ASBRs
- Routers trying to reach an external network use these.
What does a Type 0x4005 Autonomous System External LSA do?
- Redistributes routes from another Autonomous System, usually from a different routing protocol into OSPFv3
- Addresses represented as Prefix, Prefix Length
What does a Type 0x2007 NSSA LSA do?
- Advertises routes redistributed into the area
- Generated by ASBRs in NSSA networks
What does a Type 0x0008 Link LSA do?
- Maps all global unicast prefixes associated with the interface to the Link Local Address of the interface
- Advertised only to a neighbor on the same link
- Advertised to the neighbors Link Local address
What does a Type 0x2009 IntraArea Prefix LSA do?
Advertises one or more prefixes that are associated with a router, stub, or transit network segment
Verify the OSPFv3 neighbors.
show ospfv3 ipv6 neighbor
Verify the OSPFv3 interface gig0/1.
show ospfv3 interface gig0/1
Display the OSPFv3 routes.
show ipv6 route ospfv3
Check to see if an interface is Passive
show ospfv3 interface gig0/1 | I Passive
Display the network type of an interface.
show ospfv3 interface gig0/1
Display the address-family on interfaces
show ospfv3 interface brief
Display the IPv4 OSPF neighbors
show ospfv3 neighbor
