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Ethernet Technologies

Subject : it-skills

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Displays switch port information for a specified interface
Trunk
With MMF cables shorter than 100 metres (to prevent over-driving the far-end receiver) and with MMF cables longer than 300 metres (to lessen the effect of differential mode delay)
Switch#show interfaces {interface} switchport
Full duplex if only one of the two stacking connectors is used; Half duplex over a shared bus if if both connectors are used

2. What CEF adjacency is used to switch packets destined for the null interface?
The Null adjacency
IEEE 802.3ab
10 Gigabit Ethernet over 9 micron SMF (1310 nm serial laser)
A switch port that has been shut down automatically due to a serious error condition

3. What are the Gigabit Ethernet autonegotiation selection priorities?
ARP requests and replies; IP packets requiring an ICMP response; IP broadcasts to be relayed; Routing protocol updates; CDP packets; Packets needing encryption; Packets triggering NAT; Other non-IP packets
Dynamic
Switch(config)#errdisable detect cause unicast-flood
1000BASE-T full duplex followed by 1000BASE-T half duplex

4. How does topology based switching work?
Forwarding Information Base
The Punt adjacency
Layer 3 routing information builds and pre-populates a single database of the entire network topology; All table lookups are performed in hardware with the longest matching destination used in forwarding
Route caching and topology based

5. What is unknown unicast flooding?
Flooding a frame with unknown destination MAC address out all ports assigned to the source port VLAN except the source port itself
Ingress queueing; Destination MAC lookup (CAM); Destination IP lookup (FIB); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Layer 3 packet rewrite; Egress queueing
With a mask value in addition to binary values to decide which keys in a table are relevant
Entry not in FIB; FIB table full; IP TTL expired; MTU exceeded; ICMP redirect; Unsupported encapsulation; Tunnelled packets requiring compression or encryption; Access list with 'log' option; NAT must be performed

6. Enables error-disable for misconfiguration of EtherChannel bundles
Switch(config)#errdisable detect cause channel-misconfig
Adjacent MAC address (6 octets); Layer 3 engine MAC address (6 octets); EtherType (2 octets)
Switch(config)#errdisable recovery interval {seconds}
Cabling specification for 10 Mbps Ethernet over Unshielded Twisted Pair (UTP) cabling

7. What is the maximum cabling distance for Fast Ethernet over 62.5/125 micron multimode fibre?
Logical Operation Unit
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF or 9 micron SMF (1300 nm laser)
400 metres half duplex and 2000 metres full duplex
Packets that have been truncated before they were fully received

8. How do Layer 2 switches provide isolation between hosts?
10 Gigabit Ethernet over 9 micron SMF (1310 nm serial laser)
Per port collision domains; Full duplex mode; Dedicated bandwidth; Error detection; Broadcast thresholds; Intelligent filtering and forwarding
IEEE 802.3ae
American National Standards Institute

9. What is the name of a Layer 3 physical interface on a switch?
Accelerated CEF (aCEF) and Distributed CEF (dCEF)
SVI
Switch#show mac address-table [address {mac-address}] [interface {interface}] [vlan {vlan}]
Native routed interface

10. What RJ-45 pins must be swapped in a Category 5 UTP crossover cable for Gigabit Ethernet?
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF or 9 micron SMF (1300 nm laser)
Entry not in FIB; FIB table full; IP TTL expired; MTU exceeded; ICMP redirect; Unsupported encapsulation; Tunnelled packets requiring compression or encryption; Access list with 'log' option; NAT must be performed
Switched virtual interface (SVI)
1 -2 on one end with 3 -6 on the other end - and 4 -5 on one end with 7 -8 on the other end

11. What is the role of a Switch Engine (SE) in first generation MLS?
100BASE-TX - 100BASE-T2 - 100BASE-T4 and 100-BASE-FX
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Static access
Listen to the first packet and put its resulting destination in the MLS cache; Route subsequent packets in the same flow based on the MLS cache

12. Enables error-disable for errors with dynamic ARP inspection
Source IPX network (/32); Destination IPX network (/32); Destination node (/48); IPX packet type (/16)
Switch(config)#errdisable detect cause arp-inspection
UTP Fast Ethernet and Gigabit Ethernet
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)

13. How are ternary combinations implemented?
Switch#show cef not-cef-switched
Gigabit Ethernet over 4 pairs EIA/TIA Category 5 UTP
With a mask value in addition to binary values to decide which keys in a table are relevant
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance

14. What is the role of a Route Processor (RP) in first generation MLS?
Logical Operation Unit
Store-and-forward
Process the first packet in a traffic flow to determine the destination
10 km

15. What are the reasons for packets being dropped by CEF?
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
10 Gigabit Ethernet over 50 or 62.5 micron MMF (850 nm serial laser)
Electromagnetic Interference
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error

16. Enables error-disable for errors with Layer 2 Protocol Tunnelling
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
Switch(config)#errdisable detect cause l2ptguard
Tunnel
Switch(config)#interface range {type}{module}/{number} [- {number}] [ - {type}{module}/{number} ...]

17. Enables error-disable when trunking encapsulation is flapping from one type to another
Switch#show ip cef {interface} [detail]
Switch(config)#errdisable detect cause dtp-flap
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
300 seconds

18. Enables error-disable for when the port link state is flapping between the up and down states
IEEE 802.3z
Feature Manager (FM) and Switching Database Manager (SDM)
Switch(config)#errdisable detect cause link-flap
CEF glean

19. What is full duplex operation?
Switch(config)#errdisable detect cause link-flap
UTP Fast Ethernet and Gigabit Ethernet
Stations can transmit and receive at the same time because switched Ethernet removes the possibility of collisions
Switch(config)#errdisable detect cause dhcp-rate-limit

20. Displays static CAM table entries
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
Creating the VLAN
Switch(config)#errdisable detect cause rootguard
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]

21. What are the supported duplex mode settings for Gigabit Ethernet on Cisco switches?
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)
Fast Ethernet over 2 pairs EIA/TIA Category 3 - 4 - 5 UTP
Per port collision domains; Full duplex mode; Dedicated bandwidth; Error detection; Broadcast thresholds; Intelligent filtering and forwarding
Full duplex only

22. Configures a switch port with a static access VLAN assignment
1 -2 on one end with 3 -6 on the other end - and 4 -5 on one end with 7 -8 on the other end
Trunk or dynamic
Switch(config-if)#switchport access vlan {vlan}
UTP Fast Ethernet and Gigabit Ethernet

23. Enables error-disable for errors with offering inline power
Switch(config)#errdisable detect cause ilpower
Switch#show running-config interface {interface}
100BASE-TX - 100BASE-T2 - 100BASE-T4 and 100-BASE-FX
FIB with adjacency table

24. What is the maximum cabling distance for 10GBASE-SR/SW?
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Carrier Sense Multiple Access Collision Detection
S = Short; L = Long; E = Extra-long
Off

25. What is WWDM?
Wide-Wavelength Division Multiplexing
Accelerated CEF (aCEF)
Switch#show running-config interface {interface}
When one station transmits at the same time as another on a shared medium

26. What is the TCAM Value and Mask for an Ethernet access list?
Switch(config-if)#description {string}
Route caching and topology based
Source MAC (/48); Destination MAC (/48); Ethertype (/16)
When one station transmits at the same time as another on a shared medium

27. What is 100BASE-FX?
Fast Ethernet over 62.5/125 micron multimode fibre (MMF) or 9 micron singlemode fibre (SMF)
SC fibre optic or RJ-45 UTP
A name assigned to a ranges of interfaces
SVI

28. What is the operational mode of a switch port that carries transparent Layer 2 VPNs?
Numeric values that represent what action to take after the TCAM lookup occurs
Tunnel
American National Standards Institute
The Discard adjacency

29. What is the administrative mode of a switch port that carries traffic for multiple VLANs?
Switch(config)#errdisable detect cause dtp-flap
Trunk or dynamic
300 seconds
In parallel revealing the best (longest) match in a single table lookup

30. Specifies the timer for automatic re-enabling of error-disabled ports
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#errdisable recovery interval {seconds}
They are dropped (ARP throttling)
IEEE 802.3z

31. What is 10BASE-T?
Switch#show mac address-table [address {mac-address}] [interface {interface}] [vlan {vlan}]
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
Fast Ethernet over 62.5/125 micron multimode fibre (MMF) or 9 micron singlemode fibre (SMF)
Cabling specification for 10 Mbps Ethernet over Unshielded Twisted Pair (UTP) cabling

32. What denotes the number of times a CEF entry has been updated since the CEF table was created?
By electrical signalling so that either end of a link can determine what speed the other end is trying to use
The CEF entry version number
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
Packets that have been truncated before they were fully received

33. What is the maximum cabling distance for 1000BASE-CX?
25 metres
Static access or dynamic
R = LAN PHY; W = WAN PHY
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]

34. Enables automatic re-enabling of error-disabled ports
300 seconds
Switch#show interfaces status err-disabled
Switch(config)#errdisable recovery cause {all | {cause-name}}
Creating the VLAN

35. What is 1000BASE-T?
1 -2 on one end with 3 -6 on the other end
Gigabit Ethernet over 4 pairs EIA/TIA Category 5 UTP
Ternary Content-Addressable Memory
Layer 3 routing information builds and pre-populates a single database of the entire network topology; All table lookups are performed in hardware with the longest matching destination used in forwarding

36. What is 10GBASE-ER/EW?
ARP requests and replies; IP packets requiring an ICMP response; IP broadcasts to be relayed; Routing protocol updates; CDP packets; Packets needing encryption; Packets triggering NAT; Other non-IP packets
Half duplex
Layer 2 destination address changed to next-hop MAC address; Layer 2 source address changed to outbound interface MAC address; Layer 3 TTL decremented by 1; Layer 3 IP checksum recalculated; Layer 2 frame checksum recalculated
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)

37. What changes are made to packets by the CEF packet rewrite engine just before forwarding?
Switch#show mac address-table dynamic [address {mac-address}] [interface {interface}] [vlan {vlan}]
10 Gigabit Ethernet over 50 or 62.5 micron MMF (850 nm serial laser)
Layer 2 destination address changed to next-hop MAC address; Layer 2 source address changed to outbound interface MAC address; Layer 3 TTL decremented by 1; Layer 3 IP checksum recalculated; Layer 2 frame checksum recalculated
Switch#show adjacency [{interface}] [summary | detail]

38. Displays a list of all interfaces in an error-disabled state
Switch#show interfaces status err-disabled
10GbE operates only at full duplex
Interconnecting switches in a campus network
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF

39. Displays dynamic CAM table entries
With a mask value in addition to binary values to decide which keys in a table are relevant
Switch#show mac address-table dynamic [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#interface vlan {vlan-id}
IEEE 802.3

40. What CEF adjacency is used to discard packets because of access list or other policy action?
Switch(config)#errdisable detect cause gbic-invalid
Source IPX network (/32); Destination IPX network (/32); Destination node (/48); IPX packet type (/16)
Switch#show ip cef
The Discard adjacency

41. Enables error-disable when an interface has been looped back
Switch(config-if)#duplex {auto | full | half}
Switch(config)#errdisable detect cause loopback
Switch(config)#errdisable detect cause {all | {cause-name}}
Layer 2 destination address changed to next-hop MAC address; Layer 2 source address changed to outbound interface MAC address; Layer 3 TTL decremented by 1; Layer 3 IP checksum recalculated; Layer 2 frame checksum recalculated

42. What is the maximum cabling distance for 10GBASE-LR/LW?
Static access
10 km
Switch(config-if)#shutdown
Logical Operation Unit

43. Enables error-disable for errors when assigning a port to a dynamic VLAN through a VMPS
Routing table and ARP table
A three-fold combination of 0 - 1 and X (don't care)
Interconnecting with existing Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH) networks
Switch(config)#errdisable detect cause vmps

44. What are the common cabling specifications for Fast Ethernet?
Switch(config-if)#switchport mode access
UTP Fast Ethernet and Gigabit Ethernet
100BASE-TX - 100BASE-T2 - 100BASE-T4 and 100-BASE-FX
CEF glean

45. What function is performed by the Feature Manager (FM)?
A station must wait its turn to transmit; it can't transmit and receive at the same time
Wide-Wavelength Division Multiplexing
Switch(config)#errdisable detect cause udld
Compiling Access Control Entries (ACE) into the TCAM table

46. What is the TCAM Value and Mask for an IPX access list?
Source IPX network (/32); Destination IPX network (/32); Destination node (/48); IPX packet type (/16)
Full duplex only
LC - MT-RJ or RJ-45
Configure the appropriate values manually on both ends of the link

47. How are the TCAM Mask/Value pairs evaluated?
The Discard adjacency
Adjacent MAC address (6 octets); Layer 3 engine MAC address (6 octets); EtherType (2 octets)
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)
In parallel revealing the best (longest) match in a single table lookup

48. What is the default duplex mode of a Gigabit Ethernet interface?
Layer 2 destination address changed to next-hop MAC address; Layer 2 source address changed to outbound interface MAC address; Layer 3 TTL decremented by 1; Layer 3 IP checksum recalculated; Layer 2 frame checksum recalculated
Accelerated CEF (aCEF)
Full duplex
Switch#show cef drop

49. What are the basic operations that a frame undergoes as it passes through a Layer 2 switch?
Institute of Electrical and Electronics Engineers
Ingress queueing; Destination MAC lookup (CAM); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Egress queueing
Off
Switch#show running-config interface {interface}

50. What is the default timer for automatic re-enabling of error-disabled ports?
300 seconds
Switch#show cef drop
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
Switch(config)#interface {type}{module}/{number}