Dynamic Routing Protocols Flashcards
What are the three types of dynamic routing protocols (regarding how they actually function)? Give an example of each.
Distance Vector - RIP
Advanced Distance Vector - EIGRP
Link-State - OSPF, IS-IS
What is the purpose of dynamic routing protocols?
To allow routers to share network topology information. The routers use this information to choose what are, according to the routing protocol, the best routes to different destinations and populate their routing tables with these routes. Without dynamic routing protocols EVERY route would have to be input manually.
How does a distance vector routing protocol determine the best route? Why does this not always result in the best routing decisions?
Comparing the number of hops necessary for each route; the route with the fewest hops is chosen.
Because link speed is ignored.
What are the two types of routing protocols (regarding what portion of the network they cover)? Give an example of each.
Internal Gateway Protocols (EIGRP, OSPF, RIP) and External Gateway Protocols (BGP).
What three tables do link-state protocols create? What is the purpose of each?
Topology Table - stores the topology
of the network.
Routing Table - stores best routes
Neighbor Table - stores neighbors
that are participating
in the routing
protocol
What path-selection algorithm does EIGRP use? What does it stand for?
DUAL (Diffused Update Algorithm)
Describe the metric that DUAL uses. What things are taken into consideration by default? What additional factors can it be configured to consider?
It’s a composite metric - it takes multiple factors into consideration. By default it uses bandwidth and delay to choose the best path. Load and reliability are optional.
View information regarding neighboring devices participating in EIGRP:
show IP EIGRP neighbors
View information about interfaces that are configured for EIGRP on a device:
show IP EIGRP interfaces
What is the only dynamic routing protocol that offers unequal-cost load balancing?
EIGRP
What are the commands associated with configuring EIGRP?
router eigrp (AS #) network (IP)
Show information regarding any routing protocols enabled on the device:
show IP protocols
Make EIGRP run classless:
R1(config)#router EIGRP (AS#)
R1(config-router)#no auto-summary
Give a summary of the steps (from the user prompt!) involved in configuring and verifying EIGRP for IPv6:
- enable
- configure terminal
- ipv6 unicast-routing
- interface [interface name]
- no shut
- ipv6 enable
- ipv6 eigrp [AS #]
- ipv6 router eigrp [AS #]
- router-id [ip-address] - (only if the router
doesn’t have an IPv4 address assigned - exit
- show ipv6 eigrp [AS #] interfaces [interface name] [detail]
In what DRP might a router be referred to as an internal router? What does this mean?
In OSPF, an internal router is a router that sits inside a particular area.