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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 mechanism does the TCAM provide for Layer 4 comparisons involving gt - lt - neq or range operators?
Routing table and ARP table
Static access
LOU registers
IEEE 802.3z

2. Disables a switch port
Tunnel
Switch(config-if)#shutdown
SVI or native routed interface
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

3. How is link speed determined on Fast Ethernet links configured to autonegotiate?
Collision domain
Switch(config)#interface range macro {name}
Native routed interface
By electrical signalling so that either end of a link can determine what speed the other end is trying to use

4. What are the symptoms of a duplex setting mismatch between two ends of a link?
Switch#show interfaces {interface} switchport
When the Spanning Tree Protocol (STP) has put the switch port in learning or forwarding state
Compiling Access Control Entries (ACE) into the TCAM table
Slow response times - low throughput - runts and other input errors on the switch ports

5. What is the standard for Gigabit Ethernet (1000 Mbps)?
IEEE 802.3z
LC - MT-RJ or RJ-45
Ingress queueing; Destination MAC lookup (CAM); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Egress queueing
Adjacent MAC address (6 octets); Layer 3 engine MAC address (6 octets); EtherType (2 octets)

6. Enables error-disable for conditions that trigger unicast flood blocking on a port
In TCAM Value entries
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error
Switch(config)#errdisable detect cause unicast-flood
Value - Mask - and Result (VMR)

7. What is Cisco's old recommendation regarding switch port speed and duplex mode?
Configure the appropriate values manually on both ends of the link
In parallel revealing the best (longest) match in a single table lookup
1000BASE-T full duplex followed by 1000BASE-T half duplex
Accelerated CEF (aCEF) and Distributed CEF (dCEF)

8. What is the name of the CEF engine that maintains routing information in software?
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
Switch(config)#errdisable detect cause security-violation
Switch(config-if)#description {string}
The Layer 3 engine

9. What packets are immediately sent to the CEF Layer 3 engine for further processing?

10. What is the maximum cabling distance for 10GBASE-ER/EW?
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance
Full duplex if only one of the two stacking connectors is used; Half duplex over a shared bus if if both connectors are used
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
40 km

11. What is 1000BASE-CX?
Gigabit Ethernet over 1 pair Shielded Twisted Pair (STP) cabling
10 Gigabit Ethernet over copper CX4 with Infiniband connectors
Source IPX network (/32); Destination IPX network (/32); Destination node (/48); IPX packet type (/16)
Forwarding Information Base

12. How are ports that are in error-disable state re-enabled by default?
10 km
On
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
Manually by administratively disabling and re-enabling the port

13. What is the maximum cabling distance for 10GBASE-LX4/LW4?
Institute of Electrical and Electronics Engineers
Compiling Access Control Entries (ACE) into the TCAM table
IEEE 802.3
300 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF

14. What is the content of TCAM Mask entries?

15. Sets the administrative mode of a switch port to access
Source IP (/32) - Destination IP (/32) - Protocol (/16) - IP ToS (/8) - Source port (/16) - Source operator (/4) - Destination port (/16) - Destination operator (/4)
Switch(config-if)#switchport mode access
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance
300 seconds

16. What are the supported duplex mode settings for Gigabit Ethernet on Cisco switches?
When the Spanning Tree Protocol (STP) has put the switch port in learning or forwarding state
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)
Full duplex only
Switch#show adjacency [{interface}] [summary | detail]

17. What is 10GBASE-CX4?
Security and QoS ACLs
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)
10 Gigabit Ethernet over copper CX4 with Infiniband connectors
By electrical signalling so that either end of a link can determine what speed the other end is trying to use

18. What is the name of the CEF engine that forwards packets in hardware?
Switch#show interfaces {interface}
The Layer 3 forwarding engine
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error
100 metres

19. What is 1000BASE-SX?
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
Trunk or dynamic
Switch#show ip cef {interface} [detail]

20. What denotes the number of times a CEF entry has been updated since the CEF table was created?
Switch(config)#mac address-table aging-time {seconds}
Per port collision domains; Full duplex mode; Dedicated bandwidth; Error detection; Broadcast thresholds; Intelligent filtering and forwarding
The CEF entry version number
UTP Fast Ethernet and Gigabit Ethernet

21. Sets the speed of a Fast Ethernet or Gigabit Ethernet interface
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#default interface {interface}
Switch(config-if)#speed {10 | 100 | 1000 | auto}
They are dropped (ARP throttling)

22. What is the default duplex mode of a 10 Mbps Ethernet interface?
Half duplex
Switched virtual interface (SVI)
100BASE-TX - 100BASE-T2 - 100BASE-T4 and 100-BASE-FX
Switch(config)#mac address-table aging-time {seconds}

23. What changes are made to packets by the CEF packet rewrite engine just before forwarding?
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
Ingress queueing; Destination MAC lookup (CAM); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Egress queueing
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
Fast Ethernet over 4 pairs EIA/TIA Category 3 - 4 - 5 UTP

24. Configures the maximum ageing time for entries in the MAC address 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
CEF punt
Layer 2 source and destination MAC addresses; Layer 3 Time-To-Live (TTL) value and header checksum
Switch(config)#mac address-table aging-time {seconds}

25. Enables error-disable when trunking encapsulation is flapping from one type to another
1000BASE-T full duplex followed by 1000BASE-T half duplex
Switch(config-if)#duplex {auto | full | half}
Switch#show ip cef {network} [{mask}] [longer-prefixes] [detail]
Switch(config)#errdisable detect cause dtp-flap

26. What is the default timer for automatic re-enabling of error-disabled ports?
300 seconds
The Punt adjacency
Switch(config)#errdisable detect cause udld
Interconnecting switches in a campus network

27. What is unknown unicast flooding?
Switch(config)#errdisable detect cause storm-control
Flooding a frame with unknown destination MAC address out all ports assigned to the source port VLAN except the source port itself
Switch(config)#errdisable detect cause channel-misconfig
A station must wait its turn to transmit; it can't transmit and receive at the same time

28. Changes an interface to a layer 3 interface and erases all layer 2 interface configurations
Switch#show ip cef {interface} [detail]
Switch(config-if)#no switchport
Cisco Express Forwarding
ANSI X3T11 FibreChannel

29. What is 1000BASE-X?
400 metres half duplex and 2000 metres full duplex
Cabling specifications for Gigabit Ethernet
Switch#show errdisable recovery
Switch(config)#errdisable detect cause dhcp-rate-limit

30. What are runts?
CEF punt
Switch(config-if)#no switchport
Collision domain
Packets that have been truncated before they were fully received

31. Enables error-disable for rate-limiting of DHCP snooping
Static access or dynamic
Switch(config)#errdisable detect cause dhcp-rate-limit
Switch(config)#interface range macro {name}
Multilayer Switching

32. What are the reasons for packets being punted by CEF?
Cabling specifications for 10 Gigabit Ethernet
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
Switch(config)#errdisable detect cause loopback
A name assigned to a ranges of interfaces

33. What are the administrative modes of Layer 2 switched interfaces?
Switch#show ip cef {interface} [detail]
Switch(config)#errdisable detect cause udld
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
Static access - trunk - tunnel or dynamic

34. Displays interface configuration information
Interconnecting with existing Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH) networks
Switch#show interfaces {interface}
Switch#show running-config interface {interface}
Through exchange of information - which means that for one end to successfully negotiate duplex mode the other end must also be set to autonegotiate

35. What is the standard for Fast Ethernet (100 Mbps)?
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance
Half duplex
IEEE 802.3u
Switch(config)#interface vlan {vlan-id}

36. Displays CEF Drop statistics with number of packets and reason for each line card
Fast Ethernet over 2 pairs EIA/TIA Category 3 - 4 - 5 UTP
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
Switch#show cef drop
Switch(config-if)#no ip route-cache cef

37. What two IOS software components are involved in TCAM operation?
Feature Manager (FM) and Switching Database Manager (SDM)
IEEE 802.3z
Fast Ethernet over 2 pairs EIA/TIA Category 5 UTP
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX

38. What is the timer range for automatic re-enabling of error-disabled ports?
Switch(config-if)#no switchport
Ingress queueing; Destination MAC lookup (CAM); Destination IP lookup (FIB); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Layer 3 packet rewrite; Egress queueing
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
From 30 seconds to 86 -400 seconds (24 hours)

39. Selects multiple switch port interfaces at the same time and enters interface configuration mode
Half duplex
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)
Dynamic
Switch(config)#interface range {type}{module}/{number} [- {number}] [ - {type}{module}/{number} ...]

40. What is full duplex operation?
Switch(config)#errdisable detect cause dtp-flap
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
10 km
Stations can transmit and receive at the same time because switched Ethernet removes the possibility of collisions

41. Displays error-disabled detection status
Interconnecting switches in a campus network
Tunnel
Switch#show errdisable detect
Logical Operation Unit

42. Enables error-disable for errors when assigning a port to a dynamic VLAN through a VMPS
Switch#show errdisable recovery
Switch(config)#errdisable detect cause vmps
Switch(config)#errdisable detect cause {all | {cause-name}}
FIB with adjacency table

43. What information is stored in CAM?
Switch(config)#errdisable detect cause pagp-flap
The table of learned MAC addresses - ports - and VLAN information
IEEE 802.3ae
Switch(config)#errdisable detect cause dtp-flap

44. What is the role of a Switch Engine (SE) in first generation MLS?
Switch#show cef drop
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
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(config-if)#no ip route-cache cef

45. What is the maximum cabling distance for 10GBASE-CX4?
15 metres
UTP Fast Ethernet and Gigabit Ethernet
In TCAM Value entries
Switch#show cef drop

46. What is 10GBASE-ER/EW?
Half duplex
A name assigned to a ranges of interfaces
1000BASE-T full duplex followed by 1000BASE-T half duplex
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)

47. What is CAM?
Multilayer Switching
The CEF epoch number
Content-Addressable Memory
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF

48. Enables error-disable for the presence of invalid GBIC or SFP modules
Switch(config)#errdisable detect cause dhcp-rate-limit
Switch(config)#errdisable detect cause gbic-invalid
Switched virtual interface (SVI)
SVI

49. What is the TCAM Value and Mask for an IP access list?
Switched virtual interface (SVI)
300 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
SVI
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)

50. Selects an interface-range macro and enters interface configuration mode
Switch(config)#interface range macro {name}
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
10 Gigabit Ethernet over copper CX4 with Infiniband connectors
10GbE operates only at full duplex