Flashcards in ICND2 Section 3 - IPv4 Routing Protocols Deck (36)
In OSPF, what's the difference between the init and 2way states?
Init specifies that the router has received a hello packet from its neighbor, but the receiving router's ID was not included in the hello packet.
2way is attained when the router receiving the hello packet sees its own Router ID within the received hello packet's neighbor field.
What are the 8 states of OSPF neighbors?
In what type of environment is an OSPF state of Attempt valid?
What kind of packet is used during the ExStart and Exchange phases?
What does DDP stand for?
Database Descriptor Packet
What kind of packets are used during the Loading phase?
What does an LSU contain?
One or several LSA's
What information is in a Network LSA?
the DR on a broadcast segment lists which routers are joined together by the segment. The LSID of the type 2 LSA is the IP interface address of the DR.
What information is in a Summary LSA?
Information about subnets in other areas
RID of ABR that advertises the LSA
In what OSPF phase do neighbors pass each other their LSA's?
What are the 2 primary timers in OSPF?
What are the default settings for the OSPF hello and dead intervals on non-serial interfaces?
Hello = 10 seconds
Dead Interval = 4*(HelloInterval)
For DROthers, what is the maximum state that they reach with each other?
List the first 3 OSPF LSAs
What info is in a Router LSA?
Directly connected interface info
What is the area scope of type 1 and 2 LSAs?
What router type advertises type 3 LSAs, and what are they used for?
ABRs advertise them.
They are used for advertising networks from one area into another.
When an ABR floods a summary LSA, what is the advertising router set to?
Itself, so the ABR looks like the one that has all of the routes directly connected.
OSPF command to set the number of paths that will be used in ECMP
How does route poisoning work?
A route that is no longer valid will be advertised with the max metric, to let all other routers know that it's no longer available.
How does split horizon work?
Do not advertise routes out an interface which is the exit interface to get to said routes.
When does EIGRP send full and partial updates?
Full on neighbor adjacency
Partial as needed when network topology changes
What are the 2 primary timers for EIGRP?
What are the default values for the Hello and Hold timers in EIGRP?
Hello = 5 seconds
Hold = 3xHello, or 15 seconds by default
What are EIGRP's 2 primary metrics?
Bandwidth and Delay
What is the multicast address for EIGRP?
Does EIGRP ever flood updates periodically?
No, only during adjacency setup or topology changes
What are the 3 required and 1 optional attributes that must pass before an EIGRP adjacency will be established?
1. Same AS number
2. Same IP subnet
3. Matching K values
1. Authentication, if configured, must match.
What is the Feasible Distance in EIGRP?
The metric of an EIGRP route on the local router.