Routing Flashcards
In what type of routing algorithm does each router sends all or some portion of its routing table only to directly connected devices?
Distance vector
What does an advanced distance vector algorithm provide that a traditional distance vector does not?
Advanced distance vector algorithms rapid convergence, use of hello mechanisms, formation of neighborships, and the ability to balance traffic over equal- and unequal-metric paths.
In what routing algorithm does each router build a picture of the network and calculates the shortest path to each known destination?
Link state
What routing algorithm is similar to distance vector protocols, but instead of looking at the distance to figure out the best loop-free path, it looks at various BGP path attributes?
Path vector
What is the purpose of a floating static route?
A floating static route is a static route that a router uses as a backup to a primary or dynamic route.
What is the default AD (administrative distance) that OSPF uses?
110
What does the EIGRP topology table contain?
The EIGRP topology table contains all of the prefixes that are advertised in that particular EIGRP autonomous system.
What is the hello timer interval that EIGRP uses on a slow interface?
60 seconds
What is the main purpose of a virtual link in an OSPF implementation?
A virtual link in OSPF provides a disconnected area with a logical path to the backbone (Area 0).
In OSPFv3, the AllDRouters designated router (DR) is represented by what address?
FF02::06
What is the administrative distance of a connect interface?
0
What is the administrative distance of a static route?
1
What is the administrative distance of EIGRP summary route?
5
What is the administrative distance of BGP?
20
What is the administrative distance of Internal EIGRP?
90
What is the administrative distance of OSPF?
110
What is the administrative distance of IS-IS?
115
What is the administrative distance of RIP?
120
What is the administrative distance of EIGRP external route?
170
What is the administrative distance of Internal and Local BGP?
200
What are the three main components of path selection?
Prefix length, administrative distance, and metric
What type of static routes can reference the outbound interface of a router?
Directly attached static routes
ip route network subnet-mask next-hop-interface-id.
What type of static route is a route whose next hop and the destination network are covered by another learned route in the RIB?
Recursive static routes
ip route network subnet-mask next-hop-ip.
What type of static route is a fully specified static route is a route that specifies both an interface and a next-hop IP address?
Fully specified static routes
ip route network subnet-mask interface-id next-hop-ip
What is a floating static route?
A static route that the router uses as a backup to a primary or dynamic route
ip route network subnet-mask next-hop-interface-id 205
What is a successor route in EIGRP?
The successor route is the route with the lowest-metric path to reach the destination network.
What is the first next-hop router for the successor route?
Successor
What is the EIGRP metric value for the lowest-metric path to reach a destination network?
Feasible distance (FD)
In EIGRP, what is the distance reported by a router to reach a particular network prefix?
Reported distance (RD)
What states that for a route to be considered a backup route, the RD received for that route must be less than the FD that is calculated locally?
Feasibility condition
What is not the current best route but a backup route that can be used if the successor route is lost?
Feasible successor
T/F: EIGRP relies on the periodic advertisement of all network prefixes, which is done with other routing protocols, such as RIP and OSPF
False
T/F: EIGRP relies on the periodic advertisement of all network prefixes, which is done with other routing protocols, such as RIP and OSPF
False
What EIGRP packet type is used for discovering EIGRP neighbors and for detecting when a neighbor is lost?
Hello
What is the EIGRP default hello timer?
5 seconds
60 sec for slower interfaces
What is the amount of time EIGRP deems the router as still reachable and functioning?
Hold time
What is the EIGRP default hold timer?
The default hold time is three times the hello time interval. So, the default is 15 seconds, and it is 180 seconds on slower links.
What EIGRP packet type is used to get specific information from a neighbor?
Request
What EIGRP packet type is used to transmit routing and reachability information with EIGRP neighbors?
Update
What EIGRP packet type is used to search for other paths during convergence?
Query
What EIGRP packet type is sent in response to a query packet?
Reply
EIGRP uses which protocol number and multicast address for communication?
IP protocol number 88. Communication happens using the multicast group address 224.0.0.10.
What contains all of the prefixes that are advertised in a particular EIGRP autonomous system?
Topology Table
What does the K1 value represent?
The minimum bandwidth of the route, in Kbps
What does the K2 value represent?
The effective load of the route, expressed as a number from 0 to 255, where 255 is 100% loading.
What does the K3 value represent?
The route delay, in tens of microseconds: Scaled delay = Delay/10.
What does the K4 value represent?
Reliability: The likelihood of successful packet transmission, expressed as a number between 0 and 255, where 255 means 100% reliability and 0 means no reliability.
What does the K5 value represent?
The minimum maximum transmission unit (MTU) size of the route, in bytes. It can be 0 or any positive integer.
How would you configure manual EIGRP route summarization in classic mode?
ip summary-address eigrp command in interface configuration mode
How would configure manual EIGRP route summarization in named mode?
summary-address command
How does OSPF calculate cost?
The cost is inversely proportional to the bandwidth of that interface, and the higher the bandwidth of an interface, the lower the cost.
Cost = 100 Mbps/Bandwidth of the Interface, in Mbps
What needs to parameters need to match for OSPF routers to from an adjacency?
Area ID, authentication, hello/ dead timers, stub area flag, and MTU
What determines which router will be the DR on a broadcast segment?
Highest OSPF priority. In the event of a tie, the router with the highest router ID wins.
What is the multicast address routers running OSPF should be able to receive these packets?
224.0.0.5