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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 type of packets can not be forwarded by CEF but are instead sent to the switch CPU for process switching in software?
Switch#show errdisable detect
Routing table and ARP table
Switch(config)#errdisable detect cause l2ptguard
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

2. Enables error-disable when an STP BPDU is received from a root bridge on an unexpected port
Packets that have been truncated before they were fully received
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 rootguard
In TCAM Value entries

3. What information is recorded in CAM as frames arrive on a switch port?
Switch#show ip cef {network} [{mask}] [longer-prefixes] [detail]
Source MAC address; Port of arrival; VLAN; Time stamp
Switch#show mac address-table [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config-if)#no ip route-cache cef

4. Displays dynamic CAM table entries
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error
Static access
Switch#show mac address-table dynamic [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#errdisable detect cause psecure-violation

5. Enables error-disable for errors when assigning a port to a dynamic VLAN through a VMPS
Switch#show cef drop
Institute of Electrical and Electronics Engineers
Switch(config)#errdisable detect cause vmps
Accelerated CEF (aCEF) and Distributed CEF (dCEF)

6. Configures the maximum ageing time for entries in the MAC address table
Institute of Electrical and Electronics Engineers
Switch(config)#mac address-table aging-time {seconds}
Switch(config)#interface vlan {vlan-id}
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error

7. Disables CEF operation globally
Accelerated CEF (aCEF) and Distributed CEF (dCEF)
Half duplex
Switch(config)#interface range {type}{module}/{number} [- {number}] [ - {type}{module}/{number} ...]
Switch(config)#no ip cef

8. What RJ-45 pins have been swapped in a Category 5 UTP crossover cable for Fast Ethernet?
The Punt adjacency
10 km
1 -2 on one end with 3 -6 on the other end
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX

9. What is the name of a Layer 3 physical interface on a switch?
SC fibre optic or RJ-45 UTP
S = Short; L = Long; E = Extra-long
10GbE operates only at full duplex
Native routed interface

10. What tables are maintained by the CEF Layer 3 forwarding engine?
The Discard adjacency
FIB with adjacency table
The CEF epoch number
Switch(config)#errdisable detect cause security-violation

11. What is the default age-out time for stale entries in the CAM table?
The Layer 3 forwarding engine
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]
Ternary Content-Addressable Memory
300 seconds

12. What is the TCAM Value and Mask for an extended IP access list using TCP/UDP?
Source IP (/32) - Destination IP (/32) - Protocol (/16) - IP ToS (/8) - Source port (/16) - Source operator (/4) - Destination port (/16) - Destination operator (/4)
The CEF epoch number
Electromagnetic Interference
LOU registers

13. What are the reasons for packets being punted by CEF?
10 km
LAN PHY and WAN PHY
IEEE 802.3z
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

14. What is 100BASE-T2?
Fast Ethernet over 2 pairs EIA/TIA Category 3 - 4 - 5 UTP
10 km
Feature Manager (FM) and Switching Database Manager (SDM)
The Layer 3 engine

15. What is the maximum cabling distance for 1000BASE-CX?
25 metres
The CEF entry version number
Compiling Access Control Entries (ACE) into the TCAM table
Native routed interface

16. Creates an interface-range macro
Native routed interface
The CEF entry version number
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Switch(config)#define interface-range {macro-name} {type} {module}/{number} [- {number}] [ - {type} {module}/{number} ...]

17. Enables error-disable for errors with dynamic ARP inspection
10 km
10GbE operates only at full duplex
Switch(config)#errdisable detect cause arp-inspection
Cabling specifications for 10 Gigabit Ethernet

18. Removes entries from the CAM table
Switch#clear mac address-table [dynamic] [address {mac-address}] [interface {interface}] [vlan {vlan}]
S = Short; L = Long; E = Extra-long
Trunk or dynamic
Ingress queueing; Destination MAC lookup (CAM); Destination IP lookup (FIB); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Layer 3 packet rewrite; Egress queueing

19. What denotes the number of times a CEF entry has been updated since the CEF table was created?
The CEF entry version number
Numeric values that represent what action to take after the TCAM lookup occurs
Through exchange of information - which means that for one end to successfully negotiate duplex mode the other end must also be set to autonegotiate
Slow response times - low throughput - runts and other input errors on the switch ports

20. Where is source and destination addresses and other relevant protocol information for access lists stored in the TCAM table?
In TCAM Value entries
Full duplex only
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
LAN PHY and WAN PHY

21. What is the administrative mode of a switch port that uses DTP to negotiate its operational mode?
Dynamic
Multilayer Switching
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(config)#errdisable detect cause psecure-violation

22. What are the Fast Ethernet autonegotiation selection priorities?
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
Cisco Express Forwarding
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
The switch port falls back to default setting of half duplex

23. What is 10GBASE-ER/EW?
SC or MT-RJ
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)
Through exchange of information - which means that for one end to successfully negotiate duplex mode the other end must also be set to autonegotiate
10GBASE-SR/SW - 10GBASE-LR/LW - 10GBASE-ER/EW - 10GBASE-LX4/LW4 - 10GBASE-CX4

24. What function is performed by the Feature Manager (FM)?
Compiling Access Control Entries (ACE) into the TCAM table
Distributed CEF (dCEF)
10 km
A proprietary connector with a high-data-rate copper cable with enhanced signal integrity and EMI performance

25. How is link duplex mode determined on Fast Ethernet links configured to autonegotiate?
Through exchange of information - which means that for one end to successfully negotiate duplex mode the other end must also be set to autonegotiate
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
Compiling Access Control Entries (ACE) into the TCAM table
Cabling specifications for 10 Gigabit Ethernet

26. What are the operational modes of a Layer 2 switched interface?
Switch(config)#errdisable detect cause link-flap
Down - static access - trunk or tunnel
Switch(config-if)#speed {10 | 100 | 1000 | auto}
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)

27. What is the TCAM Value and Mask for an IP access list?
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)
Route caching and topology based
10GbE operates only at full duplex

28. What is FIB?
Manually by administratively disabling and re-enabling the port
Forwarding Information Base
Switch(config)#errdisable detect cause security-violation
Switch#show adjacency [{interface}] [summary | detail]

29. What is LAN PHY used for?
Switch(config)#errdisable detect cause arp-inspection
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
They are dropped (ARP throttling)
Interconnecting switches in a campus network

30. What is CAM?
Native routed interface
Content-Addressable Memory
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8)
By electrical signalling so that either end of a link can determine what speed the other end is trying to use

31. What is the DTP negotiation mode of a switch port configured as trunk?
Native routed interface
On
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]
Dynamic

32. What are the basic operations that a frame undergoes as it passes through a Layer 2 switch?
Switch#show ip cef {interface} [detail]
Ingress queueing; Destination MAC lookup (CAM); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Egress queueing
10 Gigabit Ethernet over 9 micron SMF (1550 nm serial laser)
Switch(config-if)#switchport access vlan {vlan}

33. What is the administrative mode of a switch port that is a member of one VLAN?
Static access or dynamic
70 km for 9 micron SMF; 100 km for 8 micron SMF
Off
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error

34. What tables are maintained by the CEF Layer 3 engine?
Native routed interface
IEEE 802.3u
Switch(config)#errdisable detect cause ilpower
Routing table and ARP table

35. What is an interface-range macro?
By Mask/Value - where each unique mask has eight value patterns associated with it
A name assigned to a ranges of interfaces
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error
Switch(config)#errdisable detect cause udld

36. Sets the duplex mode of an Ethernet or Fast Ethernet interface
Switch#show interfaces status err-disabled
IEEE 802.3u
Switch(config-if)#duplex {auto | full | half}
Accelerated CEF (aCEF) and Distributed CEF (dCEF)

37. What information is stored in TCAM?
Switch#show ip cef
10 km
Switch(config)#errdisable detect cause pagp-flap
Security and QoS ACLs

38. What is the maximum cabling distance for Fast Ethernet over singlemode fibre?
Cabling specifications for 10 Gigabit Ethernet
10 km
Switch#show adjacency [{interface}] [summary | detail]
Switch(config)#errdisable detect cause channel-misconfig

39. What is the administrative mode of a switch port that carries transparent Layer 2 VPNs?
Carrier Sense Multiple Access Collision Detection
Switch#show running-config interface {interface}
LC - MT-RJ or RJ-45
Tunnel

40. When should CEF be disabled?
Only temporarily for debugging purposes
The Drop adjacency
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
Switch(config)#mac address-table static {mac-address} vlan {vlan} interface {interface}

41. What are the types of layer 3 switched interfaces
Static access
SVI or native routed interface
Switch(config)#interface {type}{module}/{number}
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF or 9 micron SMF (1300 nm laser)

42. What is the maximum cabling distance for Ethernet - Fast Ethernet and Gigabit Ethernet over UTP cabling?
The Drop adjacency
SC fibre optic or RJ-45 UTP
Trunk
100 metres

43. What happens to subsequent packets destined for FIB entries in CEF glean state?
10 km
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)
They are dropped (ARP throttling)
By electrical signalling so that either end of a link can determine what speed the other end is trying to use

44. What is the content of TCAM Result entries?
Numeric values that represent what action to take after the TCAM lookup occurs
Gigabit Ethernet over 1 pair 8 or 9 micron SMF (1550 nm laser)
LOU registers
Forwarding Information Base

45. What information is stored in CAM?
SC fibre optic or RJ-45 UTP
The table of learned MAC addresses - ports - and VLAN information
IEEE 802.3u
Switch(config)#errdisable detect cause loopback

46. What CEF optimisation technique cache FIB entries in switch line cards?
Switch(config)#errdisable detect cause unicast-flood
Accelerated CEF (aCEF)
Switch#clear mac address-table [dynamic] [address {mac-address}] [interface {interface}] [vlan {vlan}]
S = Short; L = Long; E = Extra-long

47. What is 1000BASE-T?
They are dropped (ARP throttling)
Gigabit Ethernet over 4 pairs EIA/TIA Category 5 UTP
Configure the appropriate values manually on both ends of the link
Carrier Sense Multiple Access Collision Detection

48. What is 1000BASE-CX?
Cabling specifications for Gigabit Ethernet
Process the first packet in a traffic flow to determine the destination
Gigabit Ethernet over 1 pair Shielded Twisted Pair (STP) cabling
Switch#show ip cef {network} [{mask}] [longer-prefixes] [detail]

49. What is 1000BASE-ZX?
Switch#show cef drop
Cabling specifications for Gigabit Ethernet
SC or MT-RJ
Gigabit Ethernet over 1 pair 8 or 9 micron SMF (1550 nm laser)

50. What CEF adjacency is used to switch packets destined for the null interface?
Switch(config)#errdisable detect cause l2ptguard
The Null adjacency
In parallel revealing the best (longest) match in a single table lookup
Switch#show ip cef {interface} [detail]