chapter 6 part 2 Flashcards
routing table ipv4 ospf (O) means what/?
intra-area route. type 1 and 2 LSA describe the details within an area.
what is an intra-area route?
Intra area routes are routes that are originated and learned in the same area. OSPF uses LSA type 1 and type 2 to advertise intra area routes. OSPF uses the type 1 and type 2 LSA to build the topology map of the area and to determine the best routes within the area. in the route table the intra area area routes are identified as O in the routing table
what is an inter-area route?
Inter area routes are routes that originated in some other OSPF area and are advertised into your area. Inter area routes are advertised with LSA type 3. The type 3 LSA is generated by Border routers
ipv4 router table symbol (O IA) means?
Summary LSAs appear in the routing table as IA (interarea routes)
- O, meaning that the route is intra-area.
- *summary routes are received from both external and internal areas and then flooded from the ABR’s into the other routers within the area network where those routers update there routing tables and mark the routes with (O IA)
ipv4 router table symbol (O E1 or O E2)?
External LSAs appear in the routing table marked as external type 1 (E1) or external type 2 (E2) routes.
what is route summerization?
used to keep link router tables small. when a link goes down in an area if the boarder router has LSA summerization installed then the ABR does not send out a type 3 LSA to other ABR’s to tell them of the change of the route.
To manually configure interarea route summarization on an ABR, use the command?
area ‘area-id’ range ‘address mask’
** This instructs the ABR to summarize routes for a specific area before injecting them into a different area, via the backbone as type 3 summary LSAs.
To manually configure interarea route summarization on an ABR IPV6, use the command?
area ‘area-id’ range ‘prefix/prefix-length’
what show commands are used to verify the multiarea OSPF?
show ip ospf neighbor, show ip ospf, show ip ospf interfaces.
what commands are used to verify specific multiarea information:
show ip protocols, show ip ospf interface brief, show ip route ospf, show ip ospf database
what does (IA) represent when using the show ip route ospf command?
IA represents interarea, which means that the route originated from another area
LSA type 1?
including a list of directly attached network prefixes and link type
LSA type 2?
identifying the routers and the network address of the multiaccess link
