Chapter 6 - EIGRP

Used to query routes from neighbors. *Sent with reliable delivery *Unicast or multicast Activity Answer - "Sent to neighbors when an alternative route to a network is required."

Query packets

Update, Query, and Reply

RTP uses reliable delivery for ______________________ , ______________________ , and ______________________ packets.

Used to acknowledge the receipt of an EIGRP message that was sent using reliable delivery. *Sent with unreliable delivery *Unicast Activity Answer - "Confirms the receipt of an EIGRP packet."

Acknowledgement packets

False The autonomous system number referred to in the EIGRP configuration is not associated with the Internet Assigned Numbers Authority (IANA) globally assigned autonomous system numbers used by external routing protocols.

True or False The autonomous system number referred to in the EIGRP configuration is associated with the Internet Assigned Numbers Authority (IANA) and are globally assigned for all routing protocols.

False The autonomous-system argument can be assigned to any 16-bit value between the number 1 and 65,535.

True or False The autonomous-system argument can only be assigned to an 8-bit value between the number 1 and 255.

True

True or False The topology table includes route entries for every destination that the router learns from its directly connected EIGRP neighbors.

False Update packets are sent as unicasts on point-to-point networks.

True or False Update packets are sent as multicast on point-to-point networks.

False. Update packets are sent only when necessary.

True or False Update packets are sent every 90 seconds so long as a route remains viable.

False. When a router discovers a new neighbor, it records the neighbor's address and interface as an entry in the neighbor table.

True or False When a router discovers a new neighbor, it records the neighbor's address and interface as an entry in the topology table.

False. Both Bandwidth and Delay are weighted equally.

True or False When calculating metrics, EIGRP affords greater weight to Bandwidth than it does to Delay.

True. The topology table contains all destinations that are advertised by neighboring routers.

True or False. EIGRP also maintains a topology table.

False. EIGRP was designed as a network layer independent routing protocol.

True or False. EIGRP makes extensive use of the network layer for segmented data traffic.

True.

True or False. One neighbor table exists for each protocol-dependent module, such as IPv4.

False. There is a separate topology table for each PDM.

True or False. There is a single topology table shared by all PDMs.

Propagates routing information to EIGRP neighbors. *Sent with reliable delivery *Unicast or multicast Activity Answer - "Unicasts information about a network to a new neighbor."

Update packets

Ethernet - 1,000 Faster Ethernet - 100 Gigabit Ethernet - 10 T1 (or slower) - 20,000

What are the (meaningful) EIGRP Delay metric values?

EIGRP Summary Route - 5 Internal EIGRP - 90 External EIGRP - 170

What are the administrative distances for EIGRP?

Hello - Used to discover other EIGRP routers in the network. Update - Used to acknowledge the receipt of any EIGRP destination packet. Acknowledgement - Used to convey routing information to known destinations. Query - Used to request specific information from a neighbor router. Reply - Used to respond to a query.

What are the five different types of packets used by EIGRP?

Update - 1 Query - 3 Reply - 4 Hello - 5

What are the four given Opcodes given for EIGRP in the curriculum?

*To suppress unnecessary update traffic, such as when an interface is a LAN interface, with no other routers connected *To increase security controls, such as preventing unknown rogue routing devices from receiving EIGRP updates

What are the two primary reasons for using the "passive-interface" command with EIGRP?

0x0102

What is the EIGRP TVL data field value for IP Internal Routes, given in hexadecimal?

Metric = ((10,000,000 / bandwidth) * (sum of delay / 10)) * 256

What is the formula to calculate EIGRP metrics?

partial update and bounded update

What terms are used to refer to the two types of EIGRP updates?

Bandwidth and Delay

What two metrics are (primarily) used by EIGRP to determine routes?

EIGRP updates contain networks that are reachable from the router sending the update. As EIGRP updates are exchanged between neighbors, the receiving router adds these entries to its EIGRP topology table.

Define Topology table.

A bounded update refers to the sending of partial updates only to the routers that are affected by the changes.

Define bounded update.

A partial update means that the update only includes information about route changes.

Define partial update.

True By default, the K fields for Bandwidth and Delay have values set to 1, whereas all others are set to 0 (indicating they are not used by EIGRP).

True or False The EIGRP parameters TLV, in the TLV Types field of an EIGRP IP packet, include K fields for determining which metrics will be used.

Enhanced Interior Gateway Routing Protocol

What does the acronym EIGRP stand for?

Reliable Transport Protocol

What does the acronym RTP stand for?

Protocol-dependent modules (PDMs).

What elements used by EIGRP are responsible for network-protocol specific tasks?

*Serves as the computational engine for EIGRP. *Guarantees loop-free and backup paths throughout the routing domain. *Stores all available backup routes for destinations so that it can quickly adapt to alternate routes.

What functions does DUAL provide?

The autonomous system number specifies the EIGRP routing process, as multiple instances of EIGRP can be running on a single network.

What information is communicated by the autonomous system number in the EIGRP Packet Header?

Hello

An EIGRP acknowledgment is an EIGRP ______________________ packet without any data.

routing information

EIGRP sends Update packets to propagate ____________________.

Distance Vectoring

EIGRP was introduced in 1992 as what type of routing protocol?

Used for neighbor discovery and to maintain neighbor adjacencies. *Sent with unreliable delivery *Multicast (on most networks) Activity Answer - "Used to form neighbor adjacencies."

Hello packets

FF02::A

Multicast EIGRP packets for IPv6 are sent to which reserved IPv6 multicast address?

01-00-5E-00-00-0A

If an EIGRP packet is encapsulated in an Ethernet frame, the destination MAC address is what multicast address?

multi-vendor

In 2013 EIGRP became a ______________________ routing protocol, meaning that it can be used by other device vendors in addition to Cisco devices.

88

In the IPv4 packet header, the protocol field is set to ______________________ to indicate EIGRP.

Maintaining the neighbor and topology tables of EIGRP routers that belong to that protocol suite Building and translating protocol-specific packets for DUAL Interfacing DUAL to the protocol-specific routing table Computing the metric and passing this information to DUAL Implementing filtering and access lists Performing redistribution functions to and from other routing protocols Redistributing routes that are learned by other routing protocols

List the specific routing tasks for each network layer protocol PDMs are responsible for, as given by the curriculum.

224.0.0.10

Multicast EIGRP packets for IPv4 use what reserved IPv4 multicast address?

Sent in response to an EIGRP query. *Sent with reliable delivery *Unicast Activity Answer - "Provides DUAL with requested network information."

Reply packets

type, length, value (TLV)

The data portion of an EIGRP message is encapsulated in a packet. This data field is called ______________________ , ______________________ , ______________________ .

True.

True or False EIGRP messages are typically encapsulated in IPv4 or IPv6 packets.

False. EIGRP sends Acknowledgment (ACK) packets when reliable delivery is used by RTP.

True or False EIGRP sends Acknowledgment (ACK) packets when utilizing TCP segmentation.

True.

True or False EIGRP updates contain only the routing information needed and are sent only to those routers that require it.

False. On most modern networks, EIGRP Hello packets are sent as multicast packets every five seconds. However, on multipoint, non-broadcast multiple access (NBMA) networks with access links of T1 (1.544 Mb/s) or slower, Hello packets are sent as unicast packets every 60 seconds.

True or False On most modern networks, EIGRP Hello packets are sent as multicast packets every 60 seconds.

True.

True or False RTP can send EIGRP packets as unicast or multicast.

True. However, Cisco later released a basic functionality of EIGRP as an open standard to the IETF, as an informational RFC. This means that other networking vendors can now implement EIGRP on their equipment to interoperate with both Cisco and non-Cisco routers running EIGRP.

True or False EIGRP was initially released as a proprietary protocol available only on Cisco devices.

False The EIGRP packet header is included with every EIGRP packet, regardless of its type.

True or False The EIGRP packet header is included only with EIGRP Hello packets.

False. Advanced features of EIGRP, such as EIGRP stub, will not be released to the IETF. As an informational RFC, Cisco will continue to maintain control of EIGRP.

True or False Advanced features of EIGRP, such as EIGRP stub, needed for the Dynamic Multipoint Virtual Private Network (DMVPN) deployment, have been released to the IETF.

False. Although "reliable" is part of its name, RTP includes both reliable delivery and unreliable delivery of EIGRP packets, similar to TCP and UDP, respectively.

True or False As a "reliable" protocol, RTP guarantees reliable delivery of EIGRP packets.

True

True or False Bounded updates help EIGRP minimize the bandwidth that is required to send EIGRP updates.

True Unreliable delivery makes sense; otherwise, there would be an endless loop of acknowledgments.

True or False EIGRP Acknowledgment packets are always sent as an unreliable unicast.

True. To conserve bandwidth, EIGRP Hello packets are sent unreliably, as an unreliable RTP packet does not require an acknowledgment.

True or False EIGRP Hello packets are sent unreliably.

False. EIGRP uses Hello packets to maintain established adjacencies. An EIGRP router assumes that as long as it receives Hello packets from a neighbor, the neighbor and its routes remain viable.

True or False EIGRP also uses Query packets to maintain established adjacencies.

False. Authentication does not encrypt the EIGRP routing updates.

True or False EIGRP authentication encrypts routing updates sent to adjacent routers.

False. Like other routing protocols, EIGRP can be configured for authentication. It is a good practice to authenticate transmitted routing information. Doing so ensures that routers only accept routing information from other routers that have been configured with the same password or authentication information.

True or False EIGRP cannot be configured for authentication.

True. However, EIGRP is still based on the key distance vector routing protocol principle, in which information about the rest of the network is learned from directly connected neighbors.

True or False EIGRP includes features of both link-state and distance vector routing protocols.

False. EIGRP is an advanced distance vector routing protocol that includes features not found in other distance vector routing protocols like RIP and IGRP.

True or False EIGRP is an advanced link-state routing protocol that includes features not found in other link-state routing protocols.

False. EIGRP has the capability for routing different protocols, including IPv4 and IPv6.

True or False EIGRP is capable of performing functions for IPv4 routing protocol exclusively.

EIGRP uses the "router eigrp {autonomous-system}" command to enable the EIGRP process.

What command is used to enable EIGRP on a Cisco IOS device?

Diffusing Update Algorithm

What does the acronym DUAL stand for?

Use the "show ip eigrp neighbors" command to view the neighbor table and verify that EIGRP has established an adjacency with its neighbors.

Which IOS command would you use to demonstrate that an EIGRP router has established adjacencies with neighbor routers by exchanging EIGRP Hello packets?

The K1 field indicates Bandwidth and is set to 1 by default.

Which K field is used to indicate Bandwidth?

The K3 field indicates Delay and is set to 1 by default.

Which K field is used to indicate Delay?