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CDP & LLDP Questions

September 20th, 2017 in SWITCH 300-115 Go to comments

Question 1

Explanation

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

Question 3

Explanation

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

Explanation

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

Explanation

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.

Reference: 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

Explanation

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

Explanation

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

Explanation

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

Explanation

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

Explanation

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)

-> No VTP information is supported in LLDP.

Comments
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  1. Ravianath
    June 29th, 2017

    Hi..
    I am going to do ccnp exam in next month.. But i dont have any dump… please help me.. my Gmail account – Ravinathrasara at gmail . com
    Thanks

  2. Anonymous
    July 3rd, 2017

    Why don’t the questions show? Only answers?

  3. Anonymous
    July 3rd, 2017

    please can anyone assist me with a valid dump email to “Barrieabubakar @ gmail . com”

  4. Anonymous
    July 3rd, 2017

    I believe only answers are shown is because Cisco is going after sites with actual questions based on copyright infringement

  5. Ravianath
    July 4th, 2017

    Where the questions….???.. how i get those questions…

  6. Tauson
    July 12th, 2017

    Hi everyone,

    I am writing CCNP Switching next month, would you guys please share with the latest dumps to practice with.

    My email address: {email not allowed}

    Thanks in advance

  7. Tauson
    July 12th, 2017

    Hi everyone,

    I am writing CCNP Switching next month, would you guys please share with the latest dumps to practice with.

    Please DM me a link to download on twitter @beingtauson

    Thanks in advance

  8. mikeSWE
    July 20th, 2017

    @Tauson

    www 110. zippyshare. com /v/PaeanjaX/file . html
    Remove the Spaces to get the latest dump from exams4all as of 18th of July 400q (many repeats) but it contains all the new DD both VCE and PDF are in the zipfile

  9. Ali
    July 26th, 2017

    @Mike

    Do you have also have dump for route and t-shoot exams?

  10. Tobby
    July 29th, 2017

    Hi,
    About question 11,
    Which two statements about CDP are true? (Choose two.)

    A. CDP uses a TLV to advertise the native VLAN
    B. CDP is not supported with SNMP
    C. CDP is supported on Frame Relay sub interfaces.
    D. CDP runs on OSI layer 2
    E. CDP runs on OSI layer 1

    Answer: AC

    According to http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/cdp/command/cdp-cr-book/cdp-cr-a1.html A. CDP uses a TLV to advertise the native VLAN is correct

    And according to https://supportforums.cisco.com/discussion/9241526/tagged-8021q-vlans-over-frame-relay C. CDP is supported on Frame Relay subinterfaces. is correct

    But CDP also runs on OSI layer 2….and D would be also correct….what do you think?

  11. Anonymous
    July 31st, 2017

    Tobby you right. i was also looking for the right ans for this que. i found A, C and D are correct. now the big que is, which two ans are correct A and C or A and D or A, C and D ????

  12. vivian
    August 2nd, 2017
  13. Anonymous
    August 6th, 2017

    Why don’t the questions show? Where to get the questions?
    I am writing CCNP Switching next month, would you guys please share with the latest dumps to practice with. (“raymangunner @ yahoo .com”)

  14. BL
    August 8th, 2017

    This question come out today.

    Which two statements about CDP are true? (Choose two)

    Answer:
    – CDP uses a TLV to advertise the native VLAN
    – CDP is supported on Frame Relay sub interface

  15. Sam
    August 14th, 2017

    Hi Guys,
    I am planing write CCNP Switching next week, would you guys please share with the latest dumps to my email.
    Please send to amilacst10ATgmail.com

    Best Regards

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    August 30th, 2017

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  17. Mike
    September 1st, 2017

    Passed using prem dev dumps… got from facebook.

  18. minuteman
    September 3rd, 2017
  19. paul
    September 13th, 2017

    Taking CCNP switching Friday, Please help me with the dump 23bold23 at gmail. com

  20. Anonymous
    September 25th, 2017

    Guys, I’m giving my CCNP next week. could you please share the updated dumps: norway.dublin at gmail . com

    Thanks in advance.

  21. Bunu
    September 28th, 2017

    Hello I have ccnp Exam next week please tell me if these 9tut dumps are enough or else please help me with dumps on bunali2002 @ yahoo . co . in

  22. Anonymous
    October 10th, 2017

    Cisco Discovery Protocol Configuration Guide

    Chapter: Cisco Discovery Protocol Version 2

    https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/cdp/configuration/xe-16/cdp-xe-16-book/nm-cdp-discover-xe.html

  23. Anonymous
    October 10th, 2017

    Type-Length-Value Fields

    Type-Length-Value (TLV) fields are blocks of information embedded in Cisco Discovery Protocol advertisements. Information in advertisements varies, and the TLV frame format allows for extending advertisements when needed.

    Cisco Discovery Protocol

    Cisco Discovery Protocol is a Layer 2, media-independent, and network-independent protocol that networking applications use to learn about nearby, directly connected devices. Cisco Discovery Protocol is enabled by default. Each device configured for Cisco Discovery Protocol advertises at least one address at which the device can receive messages and sends periodic advertisements (messages) to the well-known multicast address 01:00:0C:CC:CC:CC. Devices discover each other by listening at that address. They also listen to messages to learn when interfaces on other devices are up or go down.

    Advertisements contain time-to-live information, which indicates the length of time a receiving device should hold Cisco Discovery Protocol information before discarding it. Advertisements supported and configured in Cisco software are sent, by default, every 60 seconds on interfaces that support Subnetwork Access Protocol (SNAP) headers. Cisco devices never forward Cisco Discovery Protocol packets. Cisco devices that support Cisco Discovery Protocol store the information received in a table. Information in this table is refreshed every time an advertisement is received, and information about a device is discarded after three advertisements from that device are missed.

    The information contained in Cisco Discovery Protocol advertisements varies based on the type of device and the installed version of the operating system. Some of the information that Cisco Discovery Protocol can learn includes:

    Cisco IOS version running on Cisco devices

    Hardware platform of devices

    IP addresses of interfaces on devices

    Locally connected devices advertising Cisco Discovery Protocol

    Interfaces active on Cisco devices, including encapsulation type

    Hostname

    Duplex setting

    VLAN Trunking Protocol (VTP) domain

    Native VLAN

  24. Anonymous
    October 10th, 2017

    https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960xr/software/15_2_6_e/configuration_guide/b_1526e_consolidated_2960xr_cg/configuring_lldp__lldp_med__and_wired_location_service.html?dtid=osscdc000283

    Configuring LLDP, LLDP-MED, and Wired Location Service

    LLDP

    To support non-Cisco devices and to allow for interoperability between other devices, the device supports the IEEE 802.1AB Link Layer Discovery Protocol (LLDP). LLDP is a neighbor discovery protocol that is used for network devices to advertise information about themselves to other devices on the network. This protocol runs over the data-link layer, which allows two systems running different network layer protocols to learn about each other.

    LLDP Supported TLVs

    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)

    LLDP and Cisco Device Stacks

    A device stack appears as a single device in the network. Therefore, LLDP discovers the device stack, not the individual stack members.
    LLDP and Cisco Medianet

    When you configure LLDP or CDP location information on a per-port basis, remote devices can send Cisco Medianet location information to the device.

    LLDP-MED

    LLDP for Media Endpoint Devices (LLDP-MED) is an extension to LLDP that operates between endpoint devices such as IP phones and network devices. It specifically provides support for voice over IP (VoIP) applications and provides additional TLVs for capabilities discovery, network policy, Power over Ethernet, inventory management and location information. By default, all LLDP-MED TLVs are enabled.

    LLDP-MED Supported TLVs

    LLDP-MED Supported TLVs

    LLDP-MED supports these TLVs:

    LLDP-MED capabilities TLV

    Allows LLDP-MED endpoints to determine the capabilities that the connected device supports and has enabled.

    Network policy TLV

    Allows both network connectivity devices and endpoints to advertise VLAN configurations and associated Layer 2 and Layer 3 attributes for the specific application on that port. For example, the switch can notify a phone of the VLAN number that it should use. The phone can connect to any device, obtain its VLAN number, and then start communicating with the call control.

    By defining a network-policy profile TLV, you can create a profile for voice and voice-signaling by specifying the values for VLAN, class of service (CoS), differentiated services code point (DSCP), and tagging mode. These profile attributes are then maintained centrally on the switch and propagated to the phone.

    Power management TLV

    Enables advanced power management between LLDP-MED endpoint and network connectivity devices. Allows devices and phones to convey power information, such as how the device is powered, power priority, and how much power the device needs.

    LLDP-MED also supports an extended power TLV to advertise fine-grained power requirements, end-point power priority, and end-point and network connectivity-device power status. LLDP is enabled and power is applied to a port, the power TLV determines the actual power requirement of the endpoint device so that the system power budget can be adjusted accordingly. The device processes the requests and either grants or denies power based on the current power budget. If the request is granted, the switch updates the power budget. If the request is denied, the device turns off power to the port, generates a syslog message, and updates the power budget. If LLDP-MED is disabled or if the endpoint does not support the LLDP-MED power TLV, the initial allocation value is used throughout the duration of the connection.

    You can change power settings by entering the power inline {auto [max max-wattage] | never | static [max max-wattage]} interface configuration command. By default the PoE interface is in auto mode; If no value is specified, the maximum is allowed (30 W).

    Inventory management TLV

    Allows an endpoint to send detailed inventory information about itself to the device, including information hardware revision, firmware version, software version, serial number, manufacturer name, model name, and asset ID TLV.

    Location TLV

    Provides location information from the device to the endpoint device. The location TLV can send this information:

    Civic location information

    Provides the civic address information and postal information. Examples of civic location information are street address, road name, and postal community name information.

    ELIN location information

    Provides the location information of a caller. The location is determined by the Emergency location identifier number (ELIN), which is a phone number that routes an emergency call to the local public safety answering point (PSAP) and which the PSAP can use to call back the emergency caller.

  25. Tawanna
    October 16th, 2017

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  26. Anonymous
    November 9th, 2017

    @Mike (“Passed using prem dev dumps… got from facebook” ) could you share the examn, please

  27. gasan
    November 13th, 2017

    Hi Guys,

    Could someone send me the latest dumps?

    gasanovic @ yahoo.com

  28. AKM
    November 25th, 2017

    I can not see questions only answers and explanation. where can I get questions from.

  29. Jiya
    November 29th, 2017

    Guys, I’m giving my CCNP next week. could you please share the updated dumps ,

    {email not allowed}

    Thanks,

  30. Jiya
    November 29th, 2017

    Guys, I’m giving my CCNP next week. could you please share the updated dumps ,

    jiya dot mehak2016 @ gmail.com

  31. Jiya
    November 29th, 2017

    Guys, I’m giving my CCNP next week. could you please share the updated dumps ,
    jiya dot {email not allowed}

  32. kktua
    November 29th, 2017

    https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/cdp/configuration/15-mt/cdp-15-mt-book/nm-cdp-discover.html
    Search subinterface ->
    Cisco Discovery Protocol is not supported on Frame Relay multipoint subinterfaces.

    As not specified in question what kind of subinterfaces, option C is false, so only A) and D) are true

    A. CDP uses a TLV to advertise the native VLAN
    D. CDP runs on OSI layer 2

    False C. CDP is supported on Frame Relay sub interfaces. (not true for multipoint subinterfaces)

  33. HARA123
    November 29th, 2017

    Hi,
    Anyone has the last valid dumps of CCNP switching please?
    Send it to rafiki.hamid @ gmail. com

    Many thanks

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    December 7th, 2017

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  35. Anonymous
    December 9th, 2017

    HI
    Can you share the dumps @{email not allowed}

  36. Anonymous
    December 9th, 2017

    can you share the dumps speeddevil4u @ gmail.com

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