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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. What CEF adjacency is used to discard packets because of access list or other policy action?
Enable error-disable for all possible causes
XENPAK - X2 - or SFP+
The Discard adjacency
When the Spanning Tree Protocol (STP) has put the switch port in learning or forwarding state

2. What is the TCAM Value and Mask for an IGMP access list?
A switch port that has been shut down automatically due to a serious error condition
Switch(config-if)#no switchport
Forwarding Information Base
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)

3. How are MAC addresses shown in the detailed output from the CEF adjacency table?
Adjacent MAC address (6 octets); Layer 3 engine MAC address (6 octets); EtherType (2 octets)
Stations can transmit and receive at the same time because switched Ethernet removes the possibility of collisions
Fast Ethernet over 2 pairs EIA/TIA Category 5 UTP
Per port collision domains; Full duplex mode; Dedicated bandwidth; Error detection; Broadcast thresholds; Intelligent filtering and forwarding

4. What is CAM?
Creating the VLAN
Content-Addressable Memory
Trunk or dynamic
SVI or native routed interface

5. What is the default age-out time for stale entries in the CAM table?
Static access - trunk - tunnel or dynamic
300 seconds
10GbE operates only at full duplex
Down - static access - trunk or tunnel

6. What is the administrative mode of a switch port that is a member of one VLAN?
Cisco Express Forwarding
Static access or dynamic
Layer 2 source and destination MAC addresses; Layer 3 Time-To-Live (TTL) value and header checksum
Half duplex

7. What is 10GBASE-ER/EW?
Switch(config)#errdisable detect cause psecure-violation
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)
When one station transmits at the same time as another on a shared medium
The adjacency table

8. Enables error-disable when an interface has been looped back
Ingress queueing; Destination MAC lookup (CAM); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Egress queueing
Switch(config)#errdisable detect cause loopback
Switch(config-if)#shutdown
Switch(config)#errdisable detect cause storm-control

9. Enables automatic re-enabling of error-disabled ports
Switch(config)#errdisable recovery cause {all | {cause-name}}
Switch(config)#default interface {interface}
Cabling specifications for Gigabit Ethernet
Switch(config)#errdisable detect cause storm-control

10. Enables error-disable for errors when assigning a port to a dynamic VLAN through a VMPS
Switch(config)#errdisable detect cause vmps
Only temporarily for debugging purposes
Security and QoS ACLs
Switch(config)#errdisable detect cause gbic-invalid

11. When should CEF be disabled?
Full duplex only
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(config)#errdisable detect cause storm-control
Only temporarily for debugging purposes

12. What are the 10GBASE-X PMD transceiver form factors used in Cisco Catalyst switches?
10GbE operates only at full duplex
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)
XENPAK - X2 - or SFP+
Native routed interface

13. What changes are made to packets by the CEF packet rewrite engine just before forwarding?
70 km for 9 micron SMF; 100 km for 8 micron SMF
They are dropped (ARP throttling)
10 km
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

14. Disables a switch port
Gigabit Interface Converter (GBIC) or Small Form factor Pluggable (SFP)
By electrical signalling so that either end of a link can determine what speed the other end is trying to use
A switch port that has been shut down automatically due to a serious error condition
Switch(config-if)#shutdown

15. Enables error-disable when an STP BPDU is received from a root bridge on an unexpected port
When one station transmits at the same time as another on a shared medium
Content-Addressable Memory
Switch(config-if)#switchport mode access
Switch(config)#errdisable detect cause rootguard

16. What is the maximum cabling distance for 10GBASE-LR/LW?
Switch(config-if)#duplex {auto | full | half}
Switch#show running-config interface {interface}
10 km
Interconnecting with existing Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH) networks

17. What RJ-45 pins must be swapped in a Category 5 UTP crossover cable for Gigabit Ethernet?
Switch#show errdisable recovery
Stations can transmit and receive at the same time because switched Ethernet removes the possibility of collisions
100BASE-TX - 100BASE-T2 - 100BASE-T4 and 100-BASE-FX
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

18. Specifies the timer for automatic re-enabling of error-disabled ports
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)
Institute of Electrical and Electronics Engineers
Switch(config)#errdisable recovery interval {seconds}
Trunk

19. Disables CEF operation globally
Switch(config)#no ip cef
Static access or trunk
IEEE 802.3z
Switch(config-if)#switchport access vlan {vlan}

20. Displays error-disabled recovery timer information
Switch#show errdisable recovery
IEEE 802.3
Switch(config)#errdisable detect cause rootguard
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF or 9 micron SMF (1300 nm laser)

21. What is the DTP negotiation mode of a switch port configured as static access?
The Discard adjacency
Switch(config)#errdisable detect cause dtp-flap
Off
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

22. What are the classes of Physical Media Dependent (PMD) interfaces defined by IEEE 802.3ae?
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
300 seconds
LAN PHY and WAN PHY
Switch(config-if)#duplex {auto | full | half}

23. What tables are maintained by the CEF Layer 3 engine?
Switch(config)#errdisable detect cause l2ptguard
In parallel revealing the best (longest) match in a single table lookup
The Discard adjacency
Routing table and ARP table

24. What denotes the number of times the CEF table has been flushed and regenerated as a whole?
The CEF epoch number
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
Multilayer Switching
15 metres

25. What is the default duplex mode of a Gigabit Ethernet interface?
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]
Gigabit Ethernet over 1 pair Shielded Twisted Pair (STP) cabling
R = LAN PHY; W = WAN PHY
Full duplex

26. What is 100BASE-FX?
The Null adjacency
Full duplex
Fast Ethernet over 62.5/125 micron multimode fibre (MMF) or 9 micron singlemode fibre (SMF)
GBIC-to-GBIC connection between stacking Catalyst switches or between any two Gigabit switch ports over a short distance

27. 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)
Route caching and topology based
400 metres half duplex and 2000 metres full duplex
Fast Ethernet over 62.5/125 micron multimode fibre (MMF) or 9 micron singlemode fibre (SMF)

28. Sets the administrative mode of a switch port to access
Switch#show running-config interface {interface}
Switch(config-if)#switchport mode access
1 -2 on one end with 3 -6 on the other end
Source MAC (/48); Destination MAC (/48); Ethertype (/16)

29. What information is stored in TCAM?
Security and QoS ACLs
Source IP (/32) - Destination IP (/32) - Protocol (/16) - IP ToS (/8) - Source port (/16) - Source operator (/4) - Destination port (/16) - Destination operator (/4)
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)
Off

30. When can a switch start to learn source MAC addresses on incoming ports?
Trunk or dynamic
A switch port that has been shut down automatically due to a serious error condition
The CEF epoch number
When the Spanning Tree Protocol (STP) has put the switch port in learning or forwarding state

31. What Ethernet ports allow for autonegotiation?
UTP Fast Ethernet and Gigabit Ethernet
Switch#show errdisable recovery
Slow response times - low throughput - runts and other input errors on the switch ports
Layer 2 source and destination MAC addresses; Layer 3 Time-To-Live (TTL) value and header checksum

32. What are the names of the two basic generations of MLS?
Route caching and topology based
Logical Operation Unit
15 metres
Switch(config)#errdisable detect cause pagp-flap

33. Displays a list with status of all interfaces
Switch(config)#errdisable detect cause arp-inspection
Switch#show interfaces status
LOU registers
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)

34. What is the content of TCAM Result entries?
Numeric values that represent what action to take after the TCAM lookup occurs
Switch(config)#define interface-range {macro-name} {type} {module}/{number} [- {number}] [ - {type} {module}/{number} ...]
Interconnecting switches in a campus network
SC or MT-RJ

35. What is the TCAM Value and Mask for an IP access list?
Switched virtual interface (SVI)
Wide-Wavelength Division Multiplexing
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)
10 Gigabit Ethernet over copper CX4 with Infiniband connectors

36. What is the maximum cabling distance for 10GBASE-ER/EW?
From 30 seconds to 86 -400 seconds (24 hours)
Switch(config)#errdisable detect cause unicast-flood
40 km
Slow response times - low throughput - runts and other input errors on the switch ports

37. What is 1000BASE-X?
10 Gigabit Ethernet over copper CX4 with Infiniband connectors
Cabling specifications for Gigabit Ethernet
Adjacent MAC address (6 octets); Layer 3 engine MAC address (6 octets); EtherType (2 octets)
Switch(config)#default interface {interface}

38. Displays entries in the Forwarding Information Base (FIB) for a specific subnet
Switch(config)#errdisable detect cause psecure-violation
400 metres half duplex and 2000 metres full duplex
Switch#show ip cef {network} [{mask}] [longer-prefixes] [detail]
Switch(config)#errdisable detect cause vmps

39. What technology was merged into the IEEE 802.3 Ethernet standard to create Gigabit Ethernet?
ANSI X3T11 FibreChannel
Switch(config)#interface range {type}{module}/{number} [- {number}] [ - {type}{module}/{number} ...]
UTP Fast Ethernet and Gigabit Ethernet
Manually by administratively disabling and re-enabling the port

40. Displays switch port information for a specified interface
Institute of Electrical and Electronics Engineers
Switch#show interfaces {interface} switchport
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
The CEF entry version number

41. What is the operational mode of a switch port that carries traffic for multiple VLANs?
Trunk
Gigabit Ethernet over 4 pairs EIA/TIA Category 5 UTP
The Layer 3 engine
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF

42. What is the name of the switching technology where good frames are received - stored for inspection and then forwarded?
Store-and-forward
Static access
From 30 seconds to 86 -400 seconds (24 hours)
Adjacent MAC address (6 octets); Layer 3 engine MAC address (6 octets); EtherType (2 octets)

43. What are the duplex modes of a GigaStack GBIC?
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
IEEE 802.3ae
10 km

44. What happens when autonegotiating of link duplex mode fails on a Fast Ethernet link?
400 metres half duplex and 2000 metres full duplex
Switch(config)#errdisable detect cause ilpower
The switch port falls back to default setting of half duplex
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX

45. What is 1000BASE-SX?
Switch(config)#default interface {interface}
Flooding a frame with unknown destination MAC address out all ports assigned to the source port VLAN except the source port itself
7 100BASE-T2 full duplex; 6 100BASE-TX full duplex; 5 100BASE-T2 half duplex; 4 100BASE-T4; 3 100BASE-TX; 2 10BASE-T full duplex; 1 10BASE-T
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)

46. What is 10GBASE-LR/LW?
10 Gigabit Ethernet over 9 micron SMF (1310 nm serial laser)
Switch#show interfaces status
Cabling specifications for Gigabit Ethernet
The adjacency table

47. How does the IEEE 802.3ae standard differ from its predecessors at the physical layer?
Switch#show interfaces {interface} switchport
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
Gigabit Ethernet over 1 pair Shielded Twisted Pair (STP) cabling
10GbE operates only at full duplex

48. What is 10GBASE-X?
The table of learned MAC addresses - ports - and VLAN information
100 metres
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Cabling specifications for 10 Gigabit Ethernet

49. What are the default error-disable detection causes?
Enable error-disable for all possible causes
Full duplex if only one of the two stacking connectors is used; Half duplex over a shared bus if if both connectors are used
A three-fold combination of 0 - 1 and X (don't care)
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

50. Displays a list of all interfaces in an error-disabled state
Off
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
Carrier Sense Multiple Access Collision Detection
Switch#show interfaces status err-disabled