CDP & LLDP Questions 4

Question 1

What is the default interval at which Cisco devices send Cisco Discovery Protocol advertisements?

A. 30 seconds
B. 60 seconds
C. 120 seconds
D. 300 seconds

Answer: B

Cisco Discovery Protocol (CDP) is a proprietary protocol designed by Cisco to help in finding information about neighboring devices. The default values are 60 seconds for advertisements. Each neighbor will keep the information contained in a packet for 180 seconds (holddown timer).

Question 2

Which statement about Cisco Discovery Protocol configuration on a Cisco switch is true?

A. CDP is enabled by default and can be disabled globally with the command no cdp run.
B. CDP is disabled by default and can be enabled globally with the command cdp enable.
C. CDP is enabled by default and can be disabled globally with the command no cdp enable.
D. CDP is disabled by default and can be enabled globally with the command cdp run.

Answer: A

Question 3

A network engineer notices inconsistent Cisco Discovery Protocol neighbors according to the diagram that is provided. The engineer notices only a single neighbor that uses Cisco Discovery Protocol, but it has several routing neighbor relationships. What would cause the output to show only the single neighbor?

A. The routers are connected via a Layer 2 switch.
B. IP routing is disabled on neighboring devices.
C. Cisco Express Forwarding is enabled locally.
D. Cisco Discovery Protocol advertisements are inconsistent between the local and remote devices.

Answer: A

CDP runs at Layer 2 so a router running CDP can see a Layer 2 switch that is directly connected to it, provided that the Layer 2 switch also runs CDP.

Question 4

After the implementation of several different types of switches from different vendors, a network engineer notices that directly connected devices that use Cisco Discovery Protocol are not visible. Which vendor-neutral protocol could be used to resolve this issue?

A. Local Area Mobility
B. Link Layer Discovery Protocol
C. NetFlow
D. Directed Response Protocol

Answer: B

تذكر دائما أن :-
CDP يعمل على اجهزة سيسكو فقط
LLDP يعمل على كل انواع اﻷجهزة الشبكية
لذلك لما يكون لديك سويتشات من مختلفة الصنع ليس من نفس الشركة فتيتخدم LLDP

Unlike CDP, Link Layer Discovery Protocol (LLDP) is an open IEEE-standard (802.1AB) Layer 2 protocol used by network devices to share information about their identities and functionality with other network elements.

Question 5

While doing network discovery using Cisco Discovery Protocol, it is found that rapid error tracking is not currently enabled. Which option must be enabled to allow for enhanced reporting mechanisms using Cisco Discovery Protocol?

A. Cisco Discovery Protocol version 2
B. Cisco IOS Embedded Event Manager
C. logging buffered
D. Cisco Discovery Protocol source interface
E. Cisco Discovery Protocol logging options

Answer: A

Cisco Discovery Protocol Version 2 provides more intelligent, device-tracking features than those available in Version 1. One of the features available is an enhanced reporting mechanism for more rapid error tracking, which helps to reduce network downtime. Errors reported include mismatched native VLAN IDs (IEEE 802.1Q) on connected ports and mismatched port-duplex states between connected devices. Messages about reported errors can be sent to the console or to a logging server.

المرجع: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/cdp/configuration/xe-3s/asr903/cdp-xe-3s-asr903-book/nm-cdp-discover.html

Question 6

A network engineer has just deployed a non-Cisco device in the network and wants to get information about it from a connected device. Cisco Discovery Protocol is not supported, so the open standard protocol must be configured. Which protocol does the network engineer configure on both devices to accomplish this?

A. IRDP
B. LLDP
C. NDP
D. LLTD

Answer: B

تذكر دائما أن :-
CDP يعمل على اجهزة سيسكو فقط
LLDP يعمل على كل انواع اﻷجهزة الشبكية
لذلك لما يكون لديك سويتشات من مختلفة الصنع ليس من نفس الشركة فتيتخدم LLDP

Unlike CDP, Link Layer Discovery Protocol (LLDP) is an open IEEE-standard (802.1AB) Layer 2 protocol used by network devices to share information about their identities and functionality with other network elements.

Question 7

Which statement about Cisco devices learning about each other through Cisco Discovery Protocol is true?

A. Each device sends periodic advertisements to multicast address 01:00:0C:CC:CC:CC.
B. Each device broadcasts periodic advertisements to all of its neighbors.
C. Each device sends periodic advertisements to a central device that builds the network topology.
D. Each device sends periodic advertisements to all IP addresses in its ARP table.

Answer: A

Cisco devices send periodic CDP announcements to the multicast destination address 01-00-0c-cc-cc-cc out each connected network interface. These multicast packets may be received by Cisco devices. This multicast destination is also used in other Cisco protocols such as VTP.

Question 8

Which option lists the information that is contained in a Cisco Discovery Protocol advertisement?

A. native VLAN IDs, port-duplex, hardware platform
B. native VLAN IDs, port-duplex, memory errors
C. native VLAN IDs, memory errors, hardware platform
D. port-duplex, hardware platform, memory errors

Answer: A

بعض المعلومات التي يحتوي  عليها البروتكول هي 
 Switch#sh cdp neighbors detail 
 

 Device ID: Switch
 Entry address(es): 
 Platform: cisco 2960, Capabilities: Switch
 Interface: FastEthernet0/1, Port ID (outgoing port): FastEthernet0/1
 Holdtime: 157
 

 Version :
 Cisco IOS Software, C2960 Software (C2960-LANBASE-M), Version 12.2(25)FX, RELEASE SOFTWARE (fc1)
 Copyright (c) 1986-2005 by Cisco Systems, Inc.
 Compiled Wed 12-Oct-05 22:05 by pt_team
 

 advertisement version: 2
 Duplex: full
 

 Switch#
Device# show cdp neighbors detail

Device ID: device.cisco.com
Entry address(es):
  IPv6 address: FE80::203:E3FF:FE6A:BF81  (link-local)
  IPv6 address: 4000::BC:0:0:C0A8:BC06  (global unicast)
Platform: cisco 3640,  Capabilities: Router
Interface: Ethernet0/1,  Port ID (outgoing port): Ethernet0/1
Holdtime : 160 sec
Version :
Cisco Internetwork Operating System Software 
IOS (tm) 3600 Software (C3640-A2IS-M), Version 12.2(25)SEB4, RELE)
advertisement version: 2
Duplex Mode: half
Native VLAN: 42
VTP Management Domain: ‘Accounting Group’

The information contained in Cisco Discovery Protocol announcements depends on the device type and the version of the operating system running on it. The following are examples of the types of information that can be contained in Cisco Discovery Protocol announcements:
+ Cisco IOS XE version running on a Cisco device
+ Duplex setting
+ Hardware platform of the device
+ Hostname
+ IP addresses of the interfaces on devices
+ Interfaces active on a Cisco device, including encapsulation type
+ Locally connected devices advertising Cisco Discovery Protocol
+ Native VLAN
+ VTP domain

Cisco Discovery Protocol Version 2 provides more intelligent device tracking features than Version 1.

Question 9

Which statement about LLDP-MED is true?

A. LLDP-MED is an extension to LLDP that operates between endpoint devices and network devices.
B. LLDP-MED is an extension to LLDP that operates only between network devices.
C. LLDP-MED is an extension to LLDP that operates only between endpoint devices.
D. LLDP-MED is an extension to LLDP that operates between routers that run BGP.

Answer: A

Media Endpoint Discovery is an enhancement of LLDP, known as LLDP-MED, that provides the following facilities:
+ Auto-discovery of LAN policies such as VLAN, Layer 2 Priority and Differentiated services (Diffserv) settings, enabling plug and play networking.
+ Device location discovery to allow creation of location databases and, in the case of Voice over Internet Protocol (VoIP), Enhanced 911 services.
+ Extended and automated power management of Power over Ethernet (PoE) end points.
+ Inventory management, allowing network administrators to track their network devices, and determine their characteristics (manufacturer, software and hardware versions, serial or asset number).

The LLDP-MED protocol extension was formally approved and published as the standard ANSI/TIA-1057 by the Telecommunications Industry Association (TIA) in April 2006.

Question 10

Which option describes a limitation of LLDP?

A. LLDP cannot provide information about VTP.
B. LLDP does not support TLVs.
C. LLDP can discover only Windows servers.
D. LLDP can discover up to two devices per port.

Answer: A

بروتوكول LLDP لايقدم معلومات عن VTP بينما بروتوكول CDP يدعم بروتوكول VTP

LLDP supports a set of attributes that it uses to discover neighbor devices. These attributes contain type, length, and value descriptions and are referred to as TLVs. LLDP supported devices can use TLVs to receive and send information to their neighbors. This protocol can advertise details such as configuration information, device capabilities, and device identity.
The switch supports these basic management TLVs. These are mandatory LLDP TLVs.
+ Port description TLV
+ System name TLV
+ System description TLV
+ System capabilities TLV
+ Management address TLV
These organizationally specific LLDP TLVs are also advertised to support LLDP-MED.
+ Port VLAN ID TLV ((IEEE 802.1 organizationally specific TLVs)
+ MAC/PHY configuration/status TLV(IEEE 802.3 organizationally specific TLVs)

لاحظ أعلاه لايوجد دعم لبروتوكول VTP
-> No VTP information is supported in LLDP.