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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 dynamic CAM table entries
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
1000BASE-T full duplex followed by 1000BASE-T half duplex
From 30 seconds to 86 -400 seconds (24 hours)
Switch#show mac address-table dynamic [address {mac-address}] [interface {interface}] [vlan {vlan}]

2. Displays static CAM table entries
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
Switch(config)#errdisable detect cause udld
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]
A three-fold combination of 0 - 1 and X (don't care)

3. What is the default age-out time for stale entries in the CAM table?
Switch(config)#errdisable detect cause security-violation
Fast Ethernet over 2 pairs EIA/TIA Category 5 UTP
Source IP (/32) - Destination IP (/32) - Protocol (/16) - IP ToS (/8) - Source port (/16) - Source operator (/4) - Destination port (/16) - Destination operator (/4)
300 seconds

4. What is the name of physical network segment where data packets can collide with one another when being sent?
Switch(config)#errdisable detect cause unicast-flood
Collision domain
Switch(config)#errdisable detect cause ilpower
Switch(config)#interface range {type}{module}/{number} [- {number}] [ - {type}{module}/{number} ...]

5. What is the maximum cabling distance for Fast Ethernet over 62.5/125 micron multimode fibre?
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
Institute of Electrical and Electronics Engineers
Switch(config)#errdisable detect cause rootguard
400 metres half duplex and 2000 metres full duplex

6. Displays the CAM table size with number of MAC addresses
GBIC-to-GBIC connection between stacking Catalyst switches or between any two Gigabit switch ports over a short distance
275 metres for 62.5 micron MMF; 550 metres for 50 micron MMF
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config-if)#description {string}

7. Displays switch port information for a specified interface
American National Standards Institute
Switch#show interfaces {interface} switchport
Switch#show interfaces {interface}
Compiling Access Control Entries (ACE) into the TCAM table

8. Enables error-disable for misconfiguration of EtherChannel bundles
Bundling together two to eight full duplex Fast Ethernet links to act as a single physical link
Switch(config)#errdisable detect cause pagp-flap
Tunnel
Switch(config)#errdisable detect cause channel-misconfig

9. What CEF adjacency is used to switch packets that can't be forwarded normally?
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Static access - trunk - tunnel or dynamic
The Drop adjacency
Source MAC (/48); Destination MAC (/48); Ethertype (/16)

10. What is TCAM overflow?
Fast Ethernet over 2 pairs EIA/TIA Category 5 UTP
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
CEF glean
Full duplex only

11. What is the maximum cabling distance for Ethernet - Fast Ethernet and Gigabit Ethernet over UTP cabling?
Switch#show running-config interface {interface}
Logical Operation Unit
100 metres
400 metres half duplex and 2000 metres full duplex

12. What CEF optimisation replicates the entire FIB table among switch line cards?
10GBASE-SR/SW - 10GBASE-LR/LW - 10GBASE-ER/EW - 10GBASE-LX4/LW4 - 10GBASE-CX4
Wide-Wavelength Division Multiplexing
Switch(config)#no ip cef
Distributed CEF (dCEF)

13. What are the reasons for packets being punted by CEF?
Incomplete adjacency; Incomplete ARP resolution; Unsupported packet features; ICMP redirect; Packets destined to the router itself; IP options present; Access list evaluation failure; Fragmentation failure
Process the first packet in a traffic flow to determine the destination
Gigabit Ethernet over 1 pair Shielded Twisted Pair (STP) cabling
Switch#show interfaces {interface} switchport

14. What is half duplex operation?

15. When are mode-conditioning patch leads required with 1000BASE-LX/LH transceivers?
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)
Numeric values that represent what action to take after the TCAM lookup occurs
Process the first packet in a traffic flow to determine the destination
Switch(config)#errdisable detect cause bpduguard

16. What is CEF?
When the Spanning Tree Protocol (STP) has put the switch port in learning or forwarding state
Cisco Express Forwarding
25 metres
Enable error-disable for all possible causes

17. What is the maximum cabling distance for 1000BASE-CX?
The Discard adjacency
Switch(config)#errdisable detect cause security-violation
25 metres
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX

18. What is a ternary combination?

19. Specifies the timer for automatic re-enabling of error-disabled ports
Switch(config)#errdisable recovery interval {seconds}
Trunk or dynamic
Creating the VLAN
The Layer 3 engine

20. What is the maximum cabling distance for 10GBASE-LR/LW?
10 km
When one station transmits at the same time as another on a shared medium
100BASE-TX - 100BASE-T2 - 100BASE-T4 and 100-BASE-FX
Wide-Wavelength Division Multiplexing

21. Enables error-disable for errors with dynamic ARP inspection
400 metres half duplex and 2000 metres full duplex
Switch#show mac address-table dynamic [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#errdisable detect cause arp-inspection
Manually by administratively disabling and re-enabling the port

22. When do collisions occur?
When one station transmits at the same time as another on a shared medium
Source MAC (/48); Destination MAC (/48); Ethertype (/16)
Slow response times - low throughput - runts and other input errors on the switch ports
Institute of Electrical and Electronics Engineers

23. What is the original standard for Ethernet (10 Mbps)?
IEEE 802.3ab
IEEE 802.3
400 metres half duplex and 2000 metres full duplex
Switch(config)#errdisable detect cause udld

24. Changes an interface to a layer 3 interface and erases all layer 2 interface configurations
American National Standards Institute
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
LAN PHY and WAN PHY
Switch(config-if)#no switchport

25. What RJ-45 pins have been swapped in a Category 5 UTP crossover cable for Fast Ethernet?
Half duplex
Full duplex if only one of the two stacking connectors is used; Half duplex over a shared bus if if both connectors are used
In TCAM Value entries
1 -2 on one end with 3 -6 on the other end

26. How is the TCAM organised?
By Mask/Value - where each unique mask has eight value patterns associated with it
Switch#show mac address-table dynamic [address {mac-address}] [interface {interface}] [vlan {vlan}]
Collision domain
Switch(config)#errdisable detect cause l2ptguard

27. What is the maximum cabling distance for 1000BASE-ZX?
Switch(config)#no ip cef
Interconnecting switches in a campus network
70 km for 9 micron SMF; 100 km for 8 micron SMF
Bundling together two to eight full duplex Fast Ethernet links to act as a single physical link

28. Removes entries from the CAM table
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
100BASE-TX - 100BASE-T2 - 100BASE-T4 and 100-BASE-FX
Switch#clear mac address-table [dynamic] [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#errdisable detect cause udld

29. What are the letters used with 10GBASE-X two-letter suffixes to specify the transceiver wavelengths?
1000BASE-T full duplex followed by 1000BASE-T half duplex
10 Gigabit Ethernet over copper CX4 with Infiniband connectors
Switch(config)#errdisable detect cause {all | {cause-name}}
S = Short; L = Long; E = Extra-long

30. What tables are maintained by the CEF Layer 3 engine?
Ingress queueing; Destination MAC lookup (CAM); Destination IP lookup (FIB); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Layer 3 packet rewrite; Egress queueing
Switch(config)#interface range {type}{module}/{number} [- {number}] [ - {type}{module}/{number} ...]
25 metres
Routing table and ARP table

31. What CEF optimisation technique cache FIB entries in switch line cards?
Accelerated CEF (aCEF)
Switch(config-if)#shutdown
Switch(config)#errdisable detect cause channel-misconfig
Full duplex

32. Displays CEF adjacency table information
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
Packets that have been truncated before they were fully received
Switch#show adjacency [{interface}] [summary | detail]
Route caching and topology based

33. What fields are rewritten in hardware before a Layer 3 packet is switched to the to egress queue of a multilayer switch?
When the Spanning Tree Protocol (STP) has put the switch port in learning or forwarding state
By electrical signalling so that either end of a link can determine what speed the other end is trying to use
Layer 2 source and destination MAC addresses; Layer 3 Time-To-Live (TTL) value and header checksum
IEEE 802.3ab

34. Sets the administrative mode of a switch port to access
Switch(config-if)#switchport mode access
300 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
American National Standards Institute
The Punt adjacency

35. What is ANSI?
American National Standards Institute
Switch#show interfaces {interface}
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance
Switch(config)#errdisable detect cause link-flap

36. What is 100BASE-T4?
Fast Ethernet over 4 pairs EIA/TIA Category 3 - 4 - 5 UTP
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)
Static access or dynamic
LC - MT-RJ or RJ-45

37. What are the 1000BASE-X transceiver module form factors used in Cisco Catalyst switches?
Switch(config)#define interface-range {macro-name} {type} {module}/{number} [- {number}] [ - {type} {module}/{number} ...]
Switch(config)#errdisable detect cause bpduguard
Gigabit Interface Converter (GBIC) or Small Form factor Pluggable (SFP)
CEF glean

38. What CEF adjacency is used to switch packets destined for the null interface?
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
Mask bits set to 1 for Value bits of interest and 0 for Value bits that don't matter
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)
The Null adjacency

39. What is 10GBASE-CX4?
Switch#show ip cef
The Discard adjacency
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance
10 Gigabit Ethernet over copper CX4 with Infiniband connectors

40. What are the basic operations that a frame undergoes as it passes through a Layer 2 switch?
Ingress queueing; Destination MAC lookup (CAM); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Egress queueing
Dynamic
Switch(config)#errdisable detect cause bpduguard
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF or 9 micron SMF (1300 nm laser)

41. Resets the configuration of a switch port to its default values
Switch(config)#default interface {interface}
Store-and-forward
Switch#show cef drop
In TCAM Value entries

42. Displays administrative and operational status for a specified interface
From 30 seconds to 86 -400 seconds (24 hours)
Switch#show interfaces {interface}
Switch#clear mac address-table [dynamic] [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#errdisable detect cause channel-misconfig

43. What is 10GBASE-X?
Cabling specifications for 10 Gigabit Ethernet
300 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]

44. What is 10GBASE-ER/EW?
A station must wait its turn to transmit; it can't transmit and receive at the same time
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)
300 seconds
Switch(config)#errdisable detect cause {all | {cause-name}}

45. What is unknown unicast flooding?
Content-Addressable Memory
40 km
Switch(config)#errdisable recovery interval {seconds}
Flooding a frame with unknown destination MAC address out all ports assigned to the source port VLAN except the source port itself

46. What is the TCAM Value and Mask for an IPX access list?
The adjacency table
Switch#show mac address-table [address {mac-address}] [interface {interface}] [vlan {vlan}]
UTP Fast Ethernet and Gigabit Ethernet
Source IPX network (/32); Destination IPX network (/32); Destination node (/48); IPX packet type (/16)

47. What are the duplex modes of a GigaStack GBIC?
Switch(config-if)#duplex {auto | full | half}
Compiling Access Control Entries (ACE) into the TCAM table
Full duplex if only one of the two stacking connectors is used; Half duplex over a shared bus if if both connectors are used
Switch#show ip cef {interface} [detail]

48. What is full duplex operation?
In parallel revealing the best (longest) match in a single table lookup
10GBASE-SR/SW - 10GBASE-LR/LW - 10GBASE-ER/EW - 10GBASE-LX4/LW4 - 10GBASE-CX4
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
Stations can transmit and receive at the same time because switched Ethernet removes the possibility of collisions

49. What is the standard for 10 Gigabit Ethernet (10GbE)?
Switch(config)#mac address-table static {mac-address} vlan {vlan} interface {interface}
Tunnel
The switch port falls back to default setting of half duplex
IEEE 802.3ae

50. What is the timer range for automatic re-enabling of error-disabled ports?
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
From 30 seconds to 86 -400 seconds (24 hours)
By Mask/Value - where each unique mask has eight value patterns associated with it
Full duplex if only one of the two stacking connectors is used; Half duplex over a shared bus if if both connectors are used