ELN DAY 2

Question 1

is a Layer 2 Cisco proprietary protocol that gathers information about neighboring (attached) Cisco devices. Since CDP is a Layer 2 protocol and does not require any IP addresses to be assigned, successful communication does not indicate routing (a Layer 3 function) is configured. CDP data is used to develop network maps by analyzing the CDP packets.

Answer 1

Cisco Discovery Protocol (CDP)

Question 2

how often a device transmits CDP packets.

Answer 2

CDP timer

Question 3

how long a device stores CDP information it receives from neighboring devices.

Answer 3

CDP holdtime

Question 4

Layer 2 devices used to define collision domains with independent bandwidth on each port. Although collision domains are defined with a switch, broadcast domains are not.

Answer 4

switches

Question 5

Three Functions of a Switch

Answer 5

address learning, making forward/filter decisions, and loop avoidance.

Question 6

automatically monitor links between all bridges(switches) in a network to prevent network loops. It is required in a network comprised of Layer 2devices if redundant links are used for backup purposes.

Answer 6

Spanning Tree Protocol (STP)

Question 7

sent every two seconds to detect changes and dynamically reconfigure the logical topology of the layer 2 network if needed.

Answer 7

BPDUs

Question 8

Does not forward, accept network traffic, or learn any MAC addresses. Port receives (but does not send) BPDUs.

Answer 8

blocking

Question 9

Sends and receives BPDUs, but does not learn MAC addresses, or forward/ process traffic. Calculating a loop-freetopology occurs when listening.

Answer 9

Listening

Question 10

Learns MAC addresses and populates the MAT to prevent flooding, but does not forward traffic.

Answer 10

Learning

Question 11

Processes and forwards traffic, while actively learning MAC addresses from incoming traffic; considered normal switch operation.

Answer 11

Forwarding

Question 12

Administratively shutdown; does not participate in STP or forward frames.

Answer 12

Disabled

Question 13

is the reference point for all other devices in the STP network. STP selects the root bridge by an election process where the lowest bridge identification wins.

Answer 13

root bridge

Question 14

based on the802.1w standard, developed to make STP convergence quicker. RSTP responds to network change and re-converge within six seconds. RSTP reduces the number of port states from five to three, which helps speed convergence.

Answer 14

Rapid Spanning Tree Protocol (RSTP)

Question 15

RSTP port state

No user data is sent over the port. This is comparable to the blocking, listening, and disabled states of the original 802.1d STP specification.

Answer 15

Discarding

Question 16

forces switch ports to immediately enter the forwarding state, bypassing the STP listening and learning states.

Answer 16

PortFast

Question 17

Physical Interfaces

Encapsulation methods utilized: HDLC, PPP, Frame Relay and X.25.

Answer 17

Serial/High Speed Serial Interface (HSSI)

Question 18

Physical interfaces

Encapsulation method utilized: ARPA (Advanced Research Projects Agency) which means that the encapsulation being utilized is Ethernet II on the interfaces.

Answer 18

Ethernet/FastEthernet/GigabitEthernet

Question 19

Basic Rate Interface (BRI) supports two 64 Kbps B-data channels and one 16 Kbps channel for transmitting control information.

Primary Rate Interface (PRI) supports 23 B channels of 64Kbps each and one 64 Kbps channel transmitting control information for a total bit rate of 1.544 Mbps.

Answer 19

ISDN

Question 20

is a virtual interface that uses a parent physical interface, allowing for network expansion despite a limited number of physical interfaces. The format for the name is listed below. Notice the decimal point in the name.

Ethernet0/1.1

A logical interface that has the parent physical interface of Ethernet0/1Sub-interfaces allow for management of multiple subnets while only having one physical interface. They are most commonly used in conjunction with VLANs.

Answer 20

Sub-Interface

Question 21

A virtual interface utilized used to encapsulate data within a separate protocol. Tunnels are used to deliver one protocol across a network using a different protocol or to provide a secure delivery across a network. The following information is needed when configuring a Tunnel interface:
Tunnel Interface Number
Tunnel Source (Beginning of the tunnel)
Tunnel Destination (End of the tunnel)

Default encapsulation method used is Generic Routing Encapsulation(GRE).

Answer 21

Tunnel

Question 22

A virtual interface configured on the router, used for maintenance/management functions. The loopback interface is commonly configured to provide an IP address when utilizing an ipunnumbered schema or to establish the router id for OSPF and BGP.

Answer 22

Loopback

Question 23

The null interface provides an alternative method of filtering traffic. Directing undesired network traffic to the null interface avoids the overhead involved with using access lists.

Answer 23

Null

Question 24

Routed Protocols IPv4, IPv6

Routing Protocols RIP, EIGRP, OSPF

Note: Routing protocols are discussed in detail later in this topic.Static Routing Manually entered routing information

Answer 24

Protocols

Question 25

Method by which an interface is configured without a dedicated IP address. If interface must provide an IP address (i.e., Traceroute), an IP unnumbered interface uses another local address as its own.

Answer 25

IP unnumbered

Question 26

Global password for privileged access. Not used if enable secret is set (mainly pre-10.3 systems).

router(config)#enable password

Answer 26

enable password

Question 27

Overrides the enable password if set.

router(config)#enable secret

If both the enable and enable secret password are set, only the enable secret password provides access.

Answer 27

enable secret

Question 28

segment configuration to reduce broadcast traffic and improve performance. A VLAN is a logical grouping of users that allows the control of information flow, independent of physical locations. A VLAN allows system administrators to logically separate a device as if it were multiple pieces of hardware.

Answer 28

VirtualLAN(VLAN)

Question 29

Security by controlling access

Efficient bandwidth by limiting broadcasts

Isolation of failure

Increased flexibility

Answer 29

VLAN advantages

Question 30

can only belong to and carry traffic for one VLAN. Upon receipt of a frame, a switch examines the destination MAC address, and checks its configuration to see if the destination interface is in the same VLAN as the source interface from which it received the frame. If the interfaces are within the same VLAN, the frame is forwarded. If not, the frame is sent to a router for inter-VLAN communication, or dropped if no router is available.

Answer 30

Access Ports

Question 31

is a 100-1000 Mbps point-to-point link between switches, or between a switch and a router. Trunk ports carry information for multiple VLANs across their links, or trunk lines.

Answer 31

trunk port

Question 32

connects two or more switches together and allows like VLANs (e.g., VLAN 10 to VLAN 10) to communicate.

Answer 32

trunking

Question 33

An older encapsulation method that adds 30 bytes of overhead data to the frame.

Answer 33

InterSwitch Link (ISL)

Question 34

Adds only four (4)bytes of overhead/data to the frame.

Answer 34

EEE 802.1q (Dot1q)

Question 35

Support 802.1Q trunks

treat each VLAN as a separate network and utilize separate STP instances for each VLAN configured on the network. PVST and PVST+ allow a VLAN trunk to forward for some VLANs while blocking others.

Answer 35

Per-VLAN STP Plus (PVST+)

Question 36

Support ISL trunk links

treat each VLAN as a separate network and utilize separate STP instances for each VLAN configured on the network. PVST and PVST+ allow a VLAN trunk to forward for some VLANs while blocking others.

Answer 36

Per-VLAN STP (PVST)

Question 37

is the addition of VLAN information into a transmitted frame, extending the Ethernet frame to 18 bytes.

Answer 37

Frame Tagging