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CDP & LLDP Questions 4

November 25th, 2018 in SWITCH 300-115 Go to comments

Question 1

Explanation

VLAN 1 is always used for CDP, VTP, PAgP traffic (except DTP uses native VLAN) even if VLAN 1 is not the native VLAN. If VLAN 1 is not the native VLAN then CDP, VTP, PAgP traffic will be tagged on the trunk.

Question 2

Question 3


Explanation

The command “no lldp transmit” disallows sending LLDP packets on the interface.

Reference: https://www.cisco.com/c/en/us/td/docs/wireless/access_point/atnms-ap-82/configuration/guide/cg-82-book/cg-chap-LLDP.pdf

Note: The “lldp receive” command enables the reception of LLDP packets on an interface.

Reference: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/5_x/nx-os/system_management/configuration/guide/sm_nx_os_cg/sm_lldp.html

Question 4

Question 5

Question 6

Explanation

The command “lldp timer rate” is used to set the sending frequency of LLDP updates in seconds. The range is 5 to 65534 seconds; the default is 30 seconds.

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_58_se/configuration/guide/2960scg/swlldp.pdf

Question 7

Explanation

LLDP and CDP can run simultaneously. LDDP uses multicast address 01-80-C2-00-00-0E and the default time between protocol frames is 30 seconds

Question 8

Question 9

Comments
  1. Armin
    February 5th, 2019

    Hi All,

    Q2
    I think B. LLDP frame has its own CRC also True.
    https://www.cisco.com/c/en/us/td/docs/routers/ncs4000/software/configure/guide/configurationguide/configurationguide_chapter_0111011.pdf (page 2)

    LLDP Frame Format
    LLDP frames use the IEEE 802.3 format, which consists of the following fields:
    • Destination address (6 bytes)—Uses a multicast address of 01-80-C2-00-00-0E.
    • Source address (6 bytes)—MAC address of the sending device or port.
    • LLDP Ethertype (2 bytes)—Uses 88-CC.
    • LLDP PDU (1500 bytes)—LLDP payload consisting of TLVs.
    • FCS (4 bytes)—Cyclic Redundancy Check (CRC) for error checking.

  2. Shab
    February 7th, 2019

    Question 8
    Which two statements about frame LLDP is true?
    A. Frame has destination multicast address
    B. LLDP data unit has sequence of Type-length-Value (TLVs)
    C. Frame has CRC

    based on : https://learningnetwork.cisco.com/docs/DOC-26851 I think A,B,C there of them are Correct?

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