ICND2 - Chapter 7
The Hello messages contain all of the information listed below. But of the following, which ones MUST match on each neighbor for them to form a neighbor relationship and exchange routes? A. Router-ID B. Hello and Dead timers C. Network Mask D. Area ID E. Known Neighbors F. Router Priority G. DR/BDR IP Address H. Authentication Password Answer in format of x, x, x, and x
B, C, D, and H
An OSPF router connected to a multiaccess network that monitors the work of the DR and takes over if the DR fails?
BDR
What is the only EGP really used today?
BGP
In OSPF, this is the special area in a multiarea design, with all nonbackbone areas needing to connect back to to here?
Backbone area
BDR?
Backup Designated Router
The BGP process of choosing the best route by working through an ordered list of comparisons of different BGP patch attributes?
Best path selection
If two companies merge networks and one uses EIGRP and other OSPF, they need at least one router running what? (EIGRP, OSPF, or Both)
Both
An OSPF packet type that lists brief descriptions of the LSAs in the OSPF LSDB?
Database Description
What is the DBD?
Database Description
A router considers a neighbor to have failed if no Hellos are received from that neighbor in this interval?
Dead interval
If a Neighbor receives a Hello message and determines that it is already listed as a Neighbor in the received Hello packet, what does it reset?
Dead timer
DR?
Designated Router
In OSPF what algorithm is used to calculate the best routes?
Dijkstra
Of the two (Distance Vector and Link State) which form of routing protocols calls for each router to send its entire routing table in each update, but only to neighbors?
Distance Vector
Of the two, Link State and Distance Vector, which one needs Loop Prevention mechanisms?
Distance Vector
RIP and IGRP are a form of Link State or Distance Vector?
Distance Vector
In OSPF, a characterization of the state of a neighbor in which the two neighbors have reach the full state?
Fully Adjacent
Once a full neighbor state is achieved, what is the only message the neighbors periodically exchange?
Hello
Interval that dictates how often Hello messages should be sent in OSPF?
Hello Interval
IGP
Interior Gateway Protocol
What is the OSPF term for a router in one area? Inter-area route Intra-area route Internal Router Area Border Router
Internal Router
What is the OSPF term for a route to a subnet inside the same area as the router? Inter-area route Intra-area route Internal Router Area Border Router
Intra-area route
What is the name of the loop prevention mechanism that prevents a countdown to infinity by limiting how high it can count?
Maximum Metric
A numeric measurement used by a routing protocol to determine how good a route is as compared to other alternate routes?
Metric
What is the name of the loop prevention mechanism that prevents a router from advertising a route out the same interface from which it learned the route?
Split Horizon
What is the name of the loop prevention mechanism that allows a router to send an update immediately when a network failure occurs?
Triggered Updates
True or False; When choosing an OSPF area all interfaces connected to the same subnet should be in the same area?
True
True or False; When choosing an OSPF area it is possible that a router is entirely internal to an area and all interfaces on that router must be assigned to the area?
True
What is used to determine which router is master and which is slave?
priority
What command is used to hard-code a router ID from within OSPF config mode?
router-id
What command is used to see info about the LSDB on the router?
show ip ospf database
What is the command to see OSPF neighbors?
show ip ospf neighbors
When adding a new neighbor, one will be known as the Master and the other a _______?
slave
What is the AD of EIGRP (internal routes)?
90
In IOS this is a table that keeps a copy of the outgoing data link headers that a router will then add to a packet before forwarding the packet, for purpose of reducing per=packet processing done by the router?
Adjacency Table
In the event that IOS needs to choose between routes learned using different routing protocols, IOS will default to using what to make the choice?
Administrative Distance
Your IP Route shows 100.200.1.4 /32 [1/0] via 10.1.4.1 What is the Metric?
0
What is the AD of a Static route?
1
Your IP Route shows 100.200.1.4 /32 [1/0] via 10.1.4.1 What is the AD?
1
What is the AD of OSPF?
110
What is the AD of RIP?
120
In OSPF, a neighbor state that implies that the router has exchanged Hellos with the neighbor and that all required parameters match? 2-way state EXSTART EXCHANGE LOADING FULL
2-way state
What is the name of the identifier assigned to an Autonomous System?
AS Number
With BGP every time the local network is advertised out of the local network it is stamped with what to prevent a loop?
AS Number
A BGP path attribute that lists the ASNs in the path?
AS_Path
What is the term for a number that defines how believable a route is?
Administrative Distance
In OSPF, which Area is the backbone of the network?
Area 0
ABR
Area Border Router
What is the OSPF term for an OSPF router with interfaces connected to the backbone area and to at least one other area? Inter-area route Intra-area route Internal Router Area Border Router
Area Border Router
What is the name of the router that separates Areas?
Area Border Router
What is the term used in OSPF for a router that connects the backbone area (Area 0) and non-backbone areas?
Area Border Router
OSPF uses the concept of ____ which break up networks based on geographical boundaries?
Areas
What is the name for a network under the administrative control of a single organization?
Autonomous System
What is the name of the router that allows you to leave your OSPF design?
Autonomous System Boundary Router
The time required for routing protocols to react to changes in the network?
Convergence
What is the term for when a network reacts to failed links and picks the new best routes?
Convergence
What is the term for when a router has a loop and keeps updating the Hop Count of RIP exponentially?
Countdown to Infinity
When forming a Neighbor relationship the Master will send a _____ to the slave to let it know what routes it is aware of?
DBD
What type of routing protocol is designed for use between different Autonomous Systems?
EGP
EGP?
Exterior Gateway Protocol
In OSPF, a neighbor state that implies that the two routers have exchanged the complete (full) contents of their respective LSDBs? 2-way state EXSTART EXCHANGE LOADING FULL
FULL
True or False: A Routing table shows all possible routes?
False
True or False; When choosing an OSPF Area an area does not need to be contiguous?
False
What is the term for a static route that has a higher AD than that of the current routing protocol?
Floating Static Route
What type of routing protocol is designed for use inside of a single Autonomous System?
IGP
What is the OSPF term for a route to a subnet in an area of which the router is not a part of? Inter-area route Intra-area route Internal Router Area Border Router
Inter-area route
A 'Hello' message between neighbors is what kind of message?
LSA
The name of a data structure in OSPF that resides in the LSDB and describes in detail the various components in a network, including routers and links (subnets)?
LSA
The acknowledgement that the other side of the possible Neighbor relationship has received a message? (sent for every message type except Hellos)
LSACK
The LSDB (Link State DB) is a collection of all routes known by the router, these are learned from what messages?
LSAs
In OSPF, the data structure in RAM of a router that holds the various LSAs?
LSDB
A slave will analyze the DBD (Database Description) it receives from the master and will if it needs more info about a route it doesn't know it sends what?
LSR
An OSPF packet used to ask a neighboring router to send a particular LSA?
LSR
What is the name of the message sent that will request information on routes that local route doesn't know about?
LSR
An OSPF packet used to send an LSA to a neighboring router?
LSU
What is sent in response to an LSR (Link State Request)?
LSU
What is the name of the message sent that will contain requested information on routes that a neighbor does not know?
LSU
OSPF and EIGRP are a form of Link State or Distance Vector?
Link State
Of the two (Distance Vector and Link State) which form of routing protocols builds a detailed database that lists links (subnets) and their state from which the best routes can be calculated?
Link State
Of the two, Link State and Distance Vector, which one does NOT need Loop Prevention mechanisms?
Link State
Of the two, Link State and Distance Vector, which one maintains a map of the network?
Link State
LSR?
Link State Request
LSU?
Link State Update
LSACK?
Link-State Acknowledgment
LSA?
Link-State Advertisement
OSPF forms relationships with its _____________?
Neighbors
What routing protocol uses cost as its metric?
OSPF
Will a routing table choose to use a more specific route, or a broader route first?
Specific route
What routing protocol uses hop count as its metric?
RIP
Of the following : RIPv1, RIPv2, EIGRP, OSPF, and IS-IS. Which does NOT support VLSM?
RIPv1
What is the name of the loop prevention mechanism that sets the metric to the max so its considered unreachable and removed from the routing table?
Route Poisoning
A method by which two routing protocol processes running in the same device can exchange routing information, thereby causing a route learned by one routing protocols to then be advertised by another?
Route Redistribution
What is implemented that requires a hierarchical design, and is used to dictate that everything in a particular area is of a certain subnet and is used to prevent area flooding ALL devices?
Route Summarization
IPv4 and IPv6 are examples of routing protocols or routed protocols?
Routed Protocols
RIP, EIGRP, OSPF, and BGP are examples of Routing Protocols or Routed Protocols?
Routing Protocols
OSPF identifies routers via a Router ID that is based on the IP of the highest __________ _______________ when OSPF starts?
active interface
If Neighbor relationships have formed and the Router-ID changes what command needs to be run to clear the OSPF process?
clear ip ospf process
Once OSPF is enabled you need to add interfaces to the Link-State DB, this is done using what command?
network
What command would you use to add network 10.23.4.0 255.255.0.0 to OSPF within area 0?
network 10.23.4.0 0.0.255.255 area 0
How many routers can an area support?
unlimited
