Chapter 10 Vocab And Command Reference - Troubleshooting Ethernet Lans

Front 1

CDP Neighbor

Back 1

A device on the other end of some communications cable that is advertising CDP updates

(Wendell, 2013 Sect. Glossary)

Front 2

Up and Up

Back 2

Jargon referring to the two interface states on a Cisco IOS router or switch (line status and protocol status, with the first "up" referring to the line status and the second "up" referring to the protocol status. An interface in this state should be able to pass data link frames.

(Wendell, 2013 Sect. Glossary)

Front 3

Connected

Back 3

The single-item status code listed by a switch show interface status command, with this status referring to a working interface.

(Wendell, 2013 Sect. Glossary)

Front 4

Error Disabled

Back 4

An interface state on LAN switches that can be the result of one of many security violations

(Wendell, 2013 Sect. Glossary)

Front 5

Problem Isolation

Back 5

The part of the trouble shooting process in which the engineer attempts to rule out possible causes of the root cause of the problem can be identified.

(Wendell, 2013 Sect. Glossary)

Front 6

Root Cause

Back 6

A troubleshooting term that refers to the reason why a problem exists, specifically a reason for which, if changed, the problem would either be solved or changed to a different problem.

(Wendell, 2013 Sect. Glossary)

Front 7

Duplex Mismatch

Back 7

On opposite ends of any Ethernet links, the condition in which one of the two devices uses full duplex logic and the other uses half duplex logic, resulting in unnecessary frame discards and retransmission on the link

(Wendell, 2013 Sect. Glossary)

Front 8

Name 5 useful things CDP discovers

Back 8

DEVICE IDENTIFIER: Typically the host name
ADDRESS LIST: Network and data link address
PORT IDENTIFIER: The interface on the remote router or switch on the other end of the link that sent the CDP advertisement,
CAPABILITIES LIST: information on what type of device it is
PLATFORM: The model and OS level running on the device

(Wendell, 2013 p. 273)

Front 9

If the line status is Administratively Down. What is the protocol status? Interface Status? and typical root cause?

Back 9

PROTOCOL STATUS: Down
INTERFACE STATUS: Disabled
TYPICAL ROOT CAUSE: The interface is configured with the shutdown command.

(Wendell, 2013 p. 278)

Front 10

LINE SWITCH AND INTERFACE CODES.

LINE STATUS: Down
PROTOCOL STATUS: Down
INTERFACE STATUS: notconnect

What is the typical root cause?

Back 10

TYPICAL ROOT CAUSE:

No cable; wrong cable pinouts; the speeds are mismatched on the two connected devices; the device on the other end of the cable is (a) powered off, (b) shutdown, or (c) error disabled

(Wendell, 2013 p. 278)

Front 11

LINE SWITCH AND INTERFACE CODES.

LINE STATUS: Up
PROTOCOL STATUS: Down
INTERFACE STATUS: notconnect

What is the typical root cause?

Back 11

TYPICAL ROOT CAUSE:

An interface up/down stat is not expected on LAN switch physical interfaces

(Wendell, 2013 p. 278)

Front 12

LINE SWITCH AND INTERFACE CODES.

LINE STATUS: Down
PROTOCOL STATUS: Down (error Disabled)
INTERFACE STATUS: err-disabled

What is the typical root cause?

Back 12

TYPICAL ROOT CAUSE:

port security has disabled the interface

(Wendell, 2013 p. 278)

Front 13

LINE SWITCH AND INTERFACE CODES.

LINE STATUS: Up
PROTOCOL STATUS: Up
INTERFACE STATUS: Connected

What is the typical root cause?

Back 13

TYPICAL ROOT CAUSE:

The interface is working

(Wendell, 2013 p. 278)

Front 14

If the IEEE autonegotiation if the speed is not known through any means what speed do you use?

Back 14

10 Mbps, half duplex.

(Wendell, 2013 p. 280)

Front 15

In IEEE autonegotiation

Can the switch successfully sense the speed without IEEE autonegotiation, by just looking at the signal on the cable.

Back 15

Yes


(Wendell, 2013 p. 280)

Front 16

In IEEE autonegotiation if the speed is 10 or 100 Mbps what is the default duplex?

Back 16

half-duplex


(Wendell, 2013 p. 280)

Front 17

In IEEE autonegotiation if the speed is 11,000 Mbps what is the default duplex?

Back 17

Full Duplex

(Wendell, 2013 p. 280)

Front 18

DESTINATION FORWARDING ENTRIES

Found

Back 18

forward the frame out the only interface listed in the matched address table entry


(Wendell, 2013 p. 286)

Front 19

DESTINATION FORWARDING ENTRIES

Not Found (unicast)

Back 19

flood the frame out all other access ports (except the incoming port) in the same VLAN, plus out trunks that have not restricted the VLAN from that trunk

(Wendell, 2013 p. 286)

Front 20

DESTINATION FORWARDING ENTRIES

Broadcast

Back 20

flood the frame with the same rules as the previous steps

(Wendell, 2013 p. 286)

Front 21

COMMANDS FOR CATALYST 2960 SWITCH CONFIGURATION
shutdown
no shutdown

Back 21

Interface subcommands that administratively disable and enable interface, respectively

(Wendell, 2013 p. 295)

Front 22

COMMANDS FOR CATALYST 2960 SWITCH CONFIGURATION

switchport port-security violation {protect|restrict\shutdown}

Back 22

Interface subcommand that tells the switch what to do if an appropriate MAC address tries to access the network through a secure switch port.

(Wendell, 2013 p. 295)

Front 23

COMMANDS FOR CATALYST 2960 SWITCH CONFIGURATION

cdp run
no cdp run

Back 23

Global command that enable and disable, respectively, CDP for the entire switch or router.

(Wendell, 2013 p. 295)

Front 24

COMMANDS FOR CATALYST 2960 SWITCH CONFIGURATION

cdp enable
no cdp enable

Back 24

Interface subcommands that enable and disable, respectively CDP for a particular interface

(Wendell, 2013 p. 295)

Front 25

COMMANDS FOR CATALYST 2960 SWITCH CONFIGURATION
speeed {auto|10|100|1000}

Back 25

Interface subcommand that manually sets the interface speed

(Wendell, 2013 p. 295)

Front 26

COMMANDS FOR CATALYST 2960 SWITCH CONFIGURATION

duplex {auto|full|half}

Back 26

Interface subcommand that manually sets the interface duplex

(Wendell, 2013 p. 295)

Front 27

EXEC COMMAND REFERENCE

show mac address-table [dynamic|static][address hw-addr][interface (type interface id here)]vlan (type vlan-id here)

Back 27

Displays the MAC address table. The security option displays information about the restricted or static settings.

(Wendell, 2013 p. 295)

Front 28

EXEC COMMAND REFERENCE

show port security [interface (put interface id here) [address]

Back 28

Displays information about security options configured on the interface

(Wendell, 2013 p. 295)

Front 29

EXEC COMMAND REFERENCE

show cdp neighbors (place number here)

Back 29

Lists one summary line of information about each neighbor found on a specific interface if an interface was listed

(Wendell, 2013 p. 295)

Front 30

EXEC COMMAND REFERENCE

show cdp neighbors (type # here)

Back 30

Lists one summary line of information about each neighbor, or just the neighbor found on a specific interface if an interface was listed

(Wendell, 2013 p. 295)

Front 31

EXEC COMMAND REFERENCE

show cdp neighbor detail

Back 31

List one large set of information (approximately 15 lines) for every neighbor

(Wendell, 2013 p. 295)

Front 32

EXEC COMMAND REFERENCE

show cdp entry (put name here)

Back 32

States whether CDP is enabled globally, and lists the default update and holdtime timers.

(Wendell, 2013 p. 295)

Front 33

EXEC COMMAND REFERENCE

show cdp interface (put # here )

Back 33

States whether CDP is enabled on each interface, or a single interface if the interface is listed, and states update and hold time timers on those interfaces.

(Wendell, 2013 p. 295)

Front 34

EXEC COMMAND REFERENCE

show cdp traffic

Back 34

Displays Global statistics for the number of CDP advertisements sent and received

(Wendell, 2013 p. 296)

Front 35

EXEC COMMAND REFERENCE

show interface (place # here)

Back 35

Displays detailed information about interface status, settings, and counters,

(Wendell, 2013 p. 296)

Front 36

EXEC COMMAND REFERENCE

show interface description

Back 36

Displays one line of information per interface, with a two-item status), includes any description that is configured on the interfaces.

(Wendell, 2013 p. 296)

Front 37

EXEC COMMAND REFERENCE

show interface (type # here) status

Back 37

Displays summary information about interface status and settings, including actual speed and duplex, a single-item status code, and whether the interface was autonegotiated.

(Wendell, 2013 p. 296)

Front 38

EXEC COMMAND REFERENCE

show interface (type # here) switchport

Back 38

Displays a large variety of configuration settings and current operational status, including VLAN trunking details, access and voice VLAN, and native VLAN

(Wendell, 2013 p. 296)

Front 39

EXEC COMMAND REFERENCE

show interface (place # here) trunk

Back 39

Lists information about the currently operational trunks (or just for the trunk listed in the command and the VLAN supported on those trunks).

(Wendell, 2013 p. 296)

Front 40

EXEC COMMAND REFERENCE

show vlan brief
show vlan

Back 40

Lists each VLAn and all interfaces assigned to that VLAN but does not include trunks

(Wendell, 2013 p. 296)

Front 41

EXEC COMMAND REFERENCE

show vlan id (place # here)

Back 41

List both access and trunk ports in the VLAN

(Wendell, 2013 p. 296)

Front 42

EXEC COMMAND REFERENCE

show vtp status

Back 42

List the current VTP status, including the current mode.

(Wendell, 2013 p. 296)