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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. When can a switch start to learn source MAC addresses on incoming ports?
Gigabit Ethernet over 1 pair 8 or 9 micron SMF (1550 nm laser)
Switch(config)#define interface-range {macro-name} {type} {module}/{number} [- {number}] [ - {type} {module}/{number} ...]
When the Spanning Tree Protocol (STP) has put the switch port in learning or forwarding state
American National Standards Institute

2. What changes are made to packets by the CEF packet rewrite engine just before forwarding?
Switch#show interfaces {interface} switchport
They are dropped (ARP throttling)
American National Standards Institute
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

3. How is the TCAM organised?
Switched virtual interface (SVI)
By Mask/Value - where each unique mask has eight value patterns associated with it
GBIC-to-GBIC connection between stacking Catalyst switches or between any two Gigabit switch ports over a short distance
Gigabit Interface Converter (GBIC) or Small Form factor Pluggable (SFP)

4. What is the default duplex mode of a Gigabit Ethernet interface?
Cabling specifications for Gigabit Ethernet
Carrier Sense Multiple Access Collision Detection
FIB with adjacency table
Full duplex

5. Displays the CAM table size with number of MAC addresses
The CEF epoch number
Source IP (/32) - Destination IP (/32) - Protocol (/16) - IP ToS (/8) - Source port (/16) - Source operator (/4) - Destination port (/16) - Destination operator (/4)
Adjacent MAC address (6 octets); Layer 3 engine MAC address (6 octets); EtherType (2 octets)
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]

6. What are the administrative modes of Layer 2 switched interfaces?
Value - Mask - and Result (VMR)
Content-Addressable Memory
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]
Static access - trunk - tunnel or dynamic

7. What is the standard for 1000BASE-T?
Switch(config-if)#no switchport
IEEE 802.3ab
Switch(config)#errdisable detect cause psecure-violation
They are dropped (ARP throttling)

8. What is the DTP negotiation mode of a switch port configured as dynamic?
Creating the VLAN
On
Switch(config)#errdisable detect cause loopback
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

9. What is the TCAM Value and Mask for an IGMP access list?
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)
40 km
Store-and-forward
10GbE operates only at full duplex

10. What are the common cabling specifications for Gigabit Ethernet?
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
Carrier Sense Multiple Access Collision Detection
Cabling specifications for Gigabit Ethernet
On

11. What is 10GBASE-SR/SW?
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
Switch#show errdisable recovery
10 Gigabit Ethernet over 50 or 62.5 micron MMF (850 nm serial laser)
Routing table and ARP table

12. What is LOU?
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)
The table of learned MAC addresses - ports - and VLAN information
Packets that have been truncated before they were fully received
Logical Operation Unit

13. What is Fast EtherChannel (FEC)?
Switch(config)#errdisable detect cause pagp-flap
Switch#show adjacency [{interface}] [summary | detail]
Partition and tune the TCAM on some Catalyst switches into areas for different functions
Bundling together two to eight full duplex Fast Ethernet links to act as a single physical link

14. What are the names of CEF optimisation techniques using specialised forwarding hardware?
R = LAN PHY; W = WAN PHY
Switch(config)#errdisable detect cause security-violation
Accelerated CEF (aCEF) and Distributed CEF (dCEF)
Native routed interface

15. Specifies the timer for automatic re-enabling of error-disabled ports
Accelerated CEF (aCEF) and Distributed CEF (dCEF)
Ingress queueing; Destination MAC lookup (CAM); Destination IP lookup (FIB); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Layer 3 packet rewrite; Egress queueing
Fast Ethernet over 2 pairs EIA/TIA Category 5 UTP
Switch(config)#errdisable recovery interval {seconds}

16. Enables error-disable for errors related to 802.1x security
By electrical signalling so that either end of a link can determine what speed the other end is trying to use
Manually by administratively disabling and re-enabling the port
Switch(config-if)#no ip route-cache cef
Switch(config)#errdisable detect cause security-violation

17. What are the reasons for packets being dropped by CEF?
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error
Process the first packet in a traffic flow to determine the destination
Cabling specifications for Gigabit Ethernet
Switch(config)#mac address-table aging-time {seconds}

18. What is 1000BASE-ZX?
Gigabit Ethernet over 1 pair 8 or 9 micron SMF (1550 nm laser)
Switch(config)#errdisable detect cause storm-control
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
Static access

19. What is FIB?
Forwarding Information Base
Switch(config)#mac address-table aging-time {seconds}
Compiling Access Control Entries (ACE) into the TCAM table
Switch#show ip cef {network} [{mask}] [longer-prefixes] [detail]

20. What CEF adjacency is used to switch packets destined for the null interface?
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
The Layer 3 engine
The Null adjacency
15 metres

21. Displays error-disabled detection status
Switch#show errdisable detect
Switch(config)#errdisable detect cause unicast-flood
Compiling Access Control Entries (ACE) into the TCAM table
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF

22. What are the 100BASE-FX connectors used in Cisco Catalyst switches?
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
SC or MT-RJ
IEEE 802.3
Switch#show mac address-table dynamic [address {mac-address}] [interface {interface}] [vlan {vlan}]

23. What is the maximum cabling distance for 10GBASE-ER/EW?
Ternary Content-Addressable Memory
The CEF epoch number
40 km
Switch(config)#interface {type}{module}/{number}

24. Displays interface configuration information
Switch#show errdisable recovery
300 seconds
Switch#show running-config interface {interface}
Mask bits set to 1 for Value bits of interest and 0 for Value bits that don't matter

25. What is 100BASE-FX?
The CEF epoch number
Switch(config)#errdisable detect cause storm-control
Security and QoS ACLs
Fast Ethernet over 62.5/125 micron multimode fibre (MMF) or 9 micron singlemode fibre (SMF)

26. What information is stored in CAM?
Content-Addressable Memory
The table of learned MAC addresses - ports - and VLAN information
Switch#show interfaces status err-disabled
40 km

27. What is the maximum cabling distance for 1000BASE-ZX?
Carrier Sense Multiple Access Collision Detection
Accelerated CEF (aCEF)
10GbE operates only at full duplex
70 km for 9 micron SMF; 100 km for 8 micron SMF

28. Configures a switch port with a static access VLAN assignment
The CEF entry version number
Switch(config-if)#switchport access vlan {vlan}
Switch(config)#errdisable detect cause storm-control
On

29. What are the operational modes of a Layer 2 switched interface?
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Per port collision domains; Full duplex mode; Dedicated bandwidth; Error detection; Broadcast thresholds; Intelligent filtering and forwarding
Down - static access - trunk or tunnel
Forwarding Information Base

30. What is ANSI?
10 Gigabit Ethernet over 9 micron SMF (1310 nm serial laser)
Switch#show interfaces status
When one station transmits at the same time as another on a shared medium
American National Standards Institute

31. What are the classes of Physical Media Dependent (PMD) interfaces defined by IEEE 802.3ae?
Configure the appropriate values manually on both ends of the link
LAN PHY and WAN PHY
By electrical signalling so that either end of a link can determine what speed the other end is trying to use
Partition and tune the TCAM on some Catalyst switches into areas for different functions

32. What is the operational mode of a switch port that carries traffic for multiple VLANs?
Packets that have been truncated before they were fully received
LC - MT-RJ or RJ-45
Trunk
1 -2 on one end with 3 -6 on the other end

33. What tables are maintained by the CEF Layer 3 engine?
SC fibre optic or RJ-45 UTP
Routing table and ARP table
The Null adjacency
Interconnecting with existing Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH) networks

34. What is the maximum cabling distance for Ethernet - Fast Ethernet and Gigabit Ethernet over UTP cabling?
Switch(config)#errdisable detect cause bpduguard
Switch#show adjacency [{interface}] [summary | detail]
100 metres
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

35. What is the administrative mode of a switch port that carries transparent Layer 2 VPNs?
Tunnel
In TCAM Value entries
Institute of Electrical and Electronics Engineers
They are dropped (ARP throttling)

36. What is LAN PHY used for?
Switch(config-if)#description {string}
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]
Interconnecting switches in a campus network
XENPAK - X2 - or SFP+

37. How does the IEEE 802.3ae standard differ from its predecessors at the physical layer?
10GbE operates only at full duplex
Switch(config)#errdisable detect cause rootguard
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch#show interfaces {interface} switchport

38. What denotes the number of times a CEF entry has been updated since the CEF table was created?
10GBASE-SR/SW - 10GBASE-LR/LW - 10GBASE-ER/EW - 10GBASE-LX4/LW4 - 10GBASE-CX4
Switch(config)#interface range macro {name}
The CEF entry version number
The Null adjacency

39. What is the DTP negotiation mode of a switch port configured as trunk?
Store-and-forward
Switch#show cef drop
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)
On

40. What is CEF?
The Layer 3 engine
Cisco Express Forwarding
Switch#show ip cef
IEEE 802.3u

41. Enables error-disable for misconfiguration of EtherChannel bundles
Switch(config)#errdisable detect cause channel-misconfig
Switch(config-if)#no ip route-cache cef
Institute of Electrical and Electronics Engineers
Creating the VLAN

42. What information is stored in TCAM?
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance
Full duplex
1000BASE-T full duplex followed by 1000BASE-T half duplex
Security and QoS ACLs

43. Enables error-disable for the presence of invalid GBIC or SFP modules
Switch(config)#errdisable detect cause gbic-invalid
Static access or trunk
Switch(config)#errdisable detect cause security-violation
A three-fold combination of 0 - 1 and X (don't care)

44. Enables error-disable when an STP BPDU is received from a root bridge on an unexpected port
Feature Manager (FM) and Switching Database Manager (SDM)
Stations can transmit and receive at the same time because switched Ethernet removes the possibility of collisions
Switch(config)#errdisable detect cause rootguard
Switch#show interfaces {interface} switchport

45. What are the duplex modes of a GigaStack GBIC?
Manually by administratively disabling and re-enabling the port
Switch(config)#errdisable detect cause pagp-flap
Full duplex if only one of the two stacking connectors is used; Half duplex over a shared bus if if both connectors are used
Cabling specification for 10 Mbps Ethernet over Unshielded Twisted Pair (UTP) cabling

46. What is the maximum cabling distance for 1000BASE-SX?
A station must wait its turn to transmit; it can't transmit and receive at the same time
Value - Mask - and Result (VMR)
275 metres for 62.5 micron MMF; 550 metres for 50 micron MMF
Switch(config-if)#description {string}

47. 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)
A three-fold combination of 0 - 1 and X (don't care)
The Discard adjacency
Value - Mask - and Result (VMR)

48. What are the letters used with 10GBASE-X two-letter suffixes to specify the PHY type?
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
Packets that have been truncated before they were fully received
R = LAN PHY; W = WAN PHY
Security and QoS ACLs

49. How are the TCAM Mask/Value pairs evaluated?
Source IPX network (/32); Destination IPX network (/32); Destination node (/48); IPX packet type (/16)
Slow response times - low throughput - runts and other input errors on the switch ports
In parallel revealing the best (longest) match in a single table lookup
Switch(config-if)#duplex {auto | full | half}

50. What is MLS?
Logical Operation Unit
Forwarding Information Base
Multilayer Switching
Bundling together two to eight full duplex Fast Ethernet links to act as a single physical link