Chapter 17 - Learning IPv4 Routes with OSPF v2 Flashcards
Examples of this include RIP, EIGRP, OSPF, and BFP.
Routing protocol
Both of these terms refer to a protocol that defines a packet structure and logical addressing. Examples include IP Version 4 and IP Version 6.
Routed protocol and routable protocol.
What are 4 main routing protocol functions?
1) Learn routing information about IP subnets from other neighbor routers.
2) Advertise routing information about IP subnets to other neighbor routers.
3) Pick the best route based on metric, if more than one possible route exists to reach a subnet.
4) Convergence - If the network topology changes, react by advertising that some routes have failed and pick a new currently best route.
What are 2 major categories of routing protocols?
Interior gateway protocols and Exterior gateway protocols
IGP and EGP
What is a routing protocol that was designed and intended for use inside a single autonomous system (AS)?
IGP
What is a routing protocol that was designed and intended for use between different autonomous systems?
EGP
This term refers to the logic and processes used by different routing protocols to solve the problem of learning all routes, choosing the best route to each subnet, and converging in reaction to changes in the internetwork.
Routing Protocol Algorithm
What are the 3 main branches of routing protocol algorithms that exist for IGP routing protocols?
1) Distance vector
2) Advanced distance vector
3) Link-state
What was the first popularly used IP distance vector protocol?
Routing Information Protocol or RIP
What IGP metric does RIP-2 use?
Hop Count
What IGP metric does OSPF use?
Cost - This is the sum of all interface cost settings for all links in a route, with the cost defaulting to be based on interface bandwidth.
What IGP metric is used by EIGRP?
Composite of bandwidth and delay - Calculated based on the route’s slowest link and the cumulative delay associated with each interface in the route.
What is the concept an IOS uses when it must choose between routes learned using different routing protocols?
Administrative Distance
What is the default admin distance for a connected route type?
0
What is the default admin distance for a static route?
1
What is the default admin distance for BGP (external routes)?
20
What is the default admin distance for EIGRP (internal routes)?
90
What is the default admin distance for IGRP?
100
What is the default admin distance for OSPF?
110
What is the default admin distance for IS-IS?
115
What is the default admin distance for RIP?
120
What is the default admin distance for EIGRP (external routes)?
170
What is the default admin distance for BGP (internal routes)?
200
To find its router ID or RID, what 3-step process does the router use when the router reloads and brings up the OSPF process?
1) If the router-id rid OSPF subcommand is configured, this value is used as the RID.
2) If any loopback interfaces have an IP configured, and the interface status is up, the router picks the highest numeric IP address among these loopback interfaces.
3) The router picks the highest numeric IP from all other interfaces whose interface status code (first status code) is up.
A network engineer can configure an interface as an OSPF passive interface, telling the router to do (or not do) what 3 things?
1) Quit sending OSPF Hellos on the interface
2) Ignore received Hellos on the interface
3) Do not form neighbor relationships over the interface
What is the difference between OSPF v2 and OSPF v3?
OSPF v2 is used with IPv4 while OSPF v3 is used with IPv6.
