day 5 Flashcards
RIP next generation (RIPng)
designed specifically for IPv6 networks
sends updates to the IPv6 multicast group FF02::9 using UDP port 521
Open shortest path first (OSPF)
supports equal cost load balancing and route authentication.
neighbors
routers on a common segment
adjacencies
routers connection to a designated router or a backup designated router
link state advertisements (LSA’s)
routers exchange LSA’s containing routing and link-state information to form an adjacency
Link state database (LSDB)
routers populate with LSA’s received from other routers..
The LSDB is maintained through the exchange of LSA’s
show ip ospf neighbor
command for mapping out OSPF connections
show ip ospf database
used for understanding the OSPF areas
show ip ospf database router
command used to gain a more complete picture of the OSPF network
OSPF router roles
Designated router (DR) Backup designated router (BDR)
designated router (DR)
sends type 2 LSA to the rest of the network
uses multicast 224.0.0.5 to non DR routers.
OSPF routers use 224.0.0.6 to send traffic back to DR
Backup designated router (BDR)
backs up the DR if it fails
OSPF router types
Backbone router, internal router, area border router, autonomous system boundry router
Backbone router
router with at least one interface attached to area 0
internal router
routers whose interfaces all belong to the same OSPF area
Area border router (ABR)
routers connected to more than one area
Autonomous system boundry router (ASBR)
routers that inject external LSA’s into the OSPF database
link state advertisements (LSA’s)
advertisements about itself and its links to all other routers in the network
1- router LSA
produced by every router and includes links, interfaces, state of links, and costs.
sent to the DR and BDR
2- network LSA
DR collects type 1 LSA’s and sends out a single type 2 representing all the routers on the link
3- summary LSA
ABR’s send one LSA representing Type 1 and Type 2 LSA’s in an area
4- ASBR Summary LSA
Originated by area border routers. sent to other areas to build the shortest path tree to an ASBR
5-AS External LSA
Originated by ASBR’s. advertises destinations external to the OSPF autonomous system. Flooded throughout the OSPF AS
7-NSSA External LSA
not flooded througout the OSPF autonomous system
standard area
Area 0 is a standard area.
Can contain LSA’s of type 1, 2, 3, 4, 5
Stub area
prevents type 5 LSA
contain type 1, 2, 3 LSA’s
totally stubby area
prevents type 5 and 3 LSA’s
only contain type 1 and 2 LSA’s
not-so-stubby-area (NSSA)
allows type 7 (NSSA external)
transit area
consists of a virtual link between areas
