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Ethernet Technologies

Subject : it-skills

Instructions:

Answer 50 questions in 15 minutes.
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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 is the DTP negotiation mode of a switch port configured as dynamic?
On
Switch(config)#interface range {type}{module}/{number} [- {number}] [ - {type}{module}/{number} ...]
Slow response times - low throughput - runts and other input errors on the switch ports
The Punt adjacency

2. What is 1000BASE-ZX?
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
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
Gigabit Ethernet over 1 pair 8 or 9 micron SMF (1550 nm laser)
Static access - trunk - tunnel or dynamic

3. What is MLS?
Multilayer Switching
Compiling Access Control Entries (ACE) into the TCAM table
Logical Operation Unit
Switch#show errdisable recovery

4. Sets the administrative mode of a switch port to access
Switch(config-if)#switchport mode access
Through exchange of information - which means that for one end to successfully negotiate duplex mode the other end must also be set to autonegotiate
Switch#show mac address-table [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config-if)#duplex {auto | full | half}

5. What tables are maintained by the CEF Layer 3 forwarding engine?
FIB with adjacency table
Fast Ethernet over 62.5/125 micron multimode fibre (MMF) or 9 micron singlemode fibre (SMF)
Switch(config)#define interface-range {macro-name} {type} {module}/{number} [- {number}] [ - {type} {module}/{number} ...]
10 Gigabit Ethernet over 50 or 62.5 micron MMF (850 nm serial laser)

6. Disables a switch port
Switch(config)#errdisable detect cause link-flap
Switch(config-if)#shutdown
10 Gigabit Ethernet over 50 or 62.5 micron MMF or 9 micron SMF (1300 nm WWDM laser)
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF

7. What is 1000BASE-SX?
1 -2 on one end with 3 -6 on the other end
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
LC - MT-RJ or RJ-45
25 metres

8. Where is source and destination addresses and other relevant protocol information for access lists stored in the TCAM table?
In TCAM Value entries
Flooding a frame with unknown destination MAC address out all ports assigned to the source port VLAN except the source port itself
Accelerated CEF (aCEF) and Distributed CEF (dCEF)
Gigabit Ethernet over 4 pairs EIA/TIA Category 5 UTP

9. What CEF adjacency is used to switch packets that can't be forwarded normally?
A switch port that has been shut down automatically due to a serious error condition
Source IP (/32); Destination IP (/32); Protocol (/16); IP ToS (/8); IGMP message type (/8)
The table of learned MAC addresses - ports - and VLAN information
The Drop adjacency

10. What are the classes of Physical Media Dependent (PMD) interfaces defined by IEEE 802.3ae?
The Discard adjacency
Switch#show cef drop
LAN PHY and WAN PHY
100 metres

11. 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
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
Logical Operation Unit
400 metres half duplex and 2000 metres full duplex

12. Enables error-disable for errors with dynamic ARP inspection
Switch#show mac address-table count [address {mac-address}] [interface {interface}] [vlan {vlan}]
A name assigned to a ranges of interfaces
Switch(config)#errdisable detect cause arp-inspection
Switch(config)#default interface {interface}

13. What is unknown unicast flooding?
Flooding a frame with unknown destination MAC address out all ports assigned to the source port VLAN except the source port itself
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
A switch port that has been shut down automatically due to a serious error condition
Half duplex

14. What is the standard for 10 Gigabit Ethernet (10GbE)?
In parallel revealing the best (longest) match in a single table lookup
IEEE 802.3ae
Forwarding Information Base
A three-fold combination of 0 - 1 and X (don't care)

15. How does topology based switching work?
On
300 seconds
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
Per port collision domains; Full duplex mode; Dedicated bandwidth; Error detection; Broadcast thresholds; Intelligent filtering and forwarding

16. Sets the duplex mode of an Ethernet or Fast Ethernet interface
Fast Ethernet over 4 pairs EIA/TIA Category 3 - 4 - 5 UTP
The Null adjacency
Switch(config-if)#duplex {auto | full | half}
Institute of Electrical and Electronics Engineers

17. What two IOS software components are involved in TCAM operation?
Distributed CEF (dCEF)
Switch(config-if)#speed {10 | 100 | 1000 | auto}
Fast Ethernet over 2 pairs EIA/TIA Category 5 UTP
Feature Manager (FM) and Switching Database Manager (SDM)

18. What RJ-45 pins have been swapped in a Category 5 UTP crossover cable for Fast Ethernet?
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
10GbE operates only at full duplex
1 -2 on one end with 3 -6 on the other end

19. What is the standard for Gigabit Ethernet (1000 Mbps)?
IEEE 802.3z
10 Gigabit Ethernet over 9 micron SMF (1310 nm serial laser)
By Mask/Value - where each unique mask has eight value patterns associated with it
Through exchange of information - which means that for one end to successfully negotiate duplex mode the other end must also be set to autonegotiate

20. What is the maximum cabling distance for 1000BASE-ZX?
Switch(config)#default interface {interface}
Switch#show running-config interface {interface}
70 km for 9 micron SMF; 100 km for 8 micron SMF
IEEE 802.3u

21. What is the maximum cabling distance for 10GBASE-LX4/LW4?
300 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
10GbE operates only at full duplex
Carrier Sense Multiple Access Collision Detection
Forwarding Information Base

22. Enables error-disable detection
66-300 metres for 50 micron MMF; 33 metres for 62.5 micron MMF
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
CEF glean
Switch(config)#errdisable detect cause {all | {cause-name}}

23. What is the default duplex mode of a 10 Mbps Ethernet interface?
IEEE 802.3ae
Dynamic
Half duplex
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

24. Displays switch port information for a specified interface
Ternary Content-Addressable Memory
Security and QoS ACLs
Switch(config)#errdisable detect cause loopback
Switch#show interfaces {interface} switchport

25. When do collisions occur?
Configure the appropriate values manually on both ends of the link
When one station transmits at the same time as another on a shared medium
Switch#clear mac address-table [dynamic] [address {mac-address}] [interface {interface}] [vlan {vlan}]
Gigabit Interface Converter (GBIC) or Small Form factor Pluggable (SFP)

26. What are the reasons for packets being dropped by CEF?
10 km
Switch(config)#errdisable detect cause l2ptguard
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]

27. Enables error-disable for misconfiguration of EtherChannel bundles
1000BASE-T full duplex followed by 1000BASE-T half duplex
Source MAC (/48); Destination MAC (/48); Ethertype (/16)
A name assigned to a ranges of interfaces
Switch(config)#errdisable detect cause channel-misconfig

28. What is TCAM overflow?
Switch#show running-config interface {interface}
When there are more access list entries and Layer 4 operations than available Mask/Value and LOU entries
Switch#clear mac address-table [dynamic] [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch(config)#errdisable detect cause psecure-violation

29. What is the administrative mode of a switch port that uses DTP to negotiate its operational mode?
R = LAN PHY; W = WAN PHY
Ingress queueing; Destination MAC lookup (CAM); Security ACL lookup (TCAM); QoS ACL lookup (TCAM); Egress queueing
Dynamic
XENPAK - X2 - or SFP+

30. Creates an interface-range macro
10 km
Compiling Access Control Entries (ACE) into the TCAM table
10 Gigabit Ethernet over copper CX4 with Infiniband connectors
Switch(config)#define interface-range {macro-name} {type} {module}/{number} [- {number}] [ - {type} {module}/{number} ...]

31. Creates a switched virtual interface (SVI) and enters interface configuration mode
10 km
Switch(config)#errdisable detect cause l2ptguard
Switch(config)#interface vlan {vlan-id}
Switch(config)#errdisable detect cause dtp-flap

32. Displays interface configuration information
Content-Addressable Memory
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
Switch#show mac address-table static [address {mac-address}] [interface {interface}] [vlan {vlan}]
Switch#show running-config interface {interface}

33. Enables error-disable for the presence of invalid GBIC or SFP modules
Fast Ethernet over 4 pairs EIA/TIA Category 3 - 4 - 5 UTP
Ternary Content-Addressable Memory
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)#errdisable detect cause gbic-invalid

34. What is the maximum cabling distance for 1000BASE-LX/LH?
Switch(config)#errdisable detect cause storm-control
550 metres for 50 or 62.5 micron MMF; 10 km for 9 micron SMF
Switch(config-if)#no ip route-cache cef
Source IP (/32) - Destination IP (/32) - Protocol (/16) - IP ToS (/8) - Source port (/16) - Source operator (/4) - Destination port (/16) - Destination operator (/4)

35. What is the maximum cabling distance for 10GBASE-ER/EW?
Switch#show ip cef {interface} [detail]
Numeric values that represent what action to take after the TCAM lookup occurs
Encapsulation failure; Unresolved address; Unsupported protocol; No valid route; No valid adjacency; Checksum error
40 km

36. Enables error-disable for errors when assigning a port to a dynamic VLAN through a VMPS
Switch(config)#errdisable detect cause security-violation
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
Switch(config)#errdisable detect cause vmps
Source IP (/32); Destination IP (/32); Protocol (/16); ICMP code (/8); ICMP type (/4); IP type of service (ToS) (/8)

37. What combinations are TCAM entries composed of?
Value - Mask - and Result (VMR)
Switch(config)#errdisable detect cause vmps
American National Standards Institute
Switch(config-if)#duplex {auto | full | half}

38. What is the administrative mode of a switch port that carries transparent Layer 2 VPNs?
Switch(config)#mac address-table aging-time {seconds}
Switch(config)#errdisable detect cause link-flap
Tunnel
A three-fold combination of 0 - 1 and X (don't care)

39. What are the symptoms of a duplex setting mismatch between two ends of a link?
FIB with adjacency table
Switch(config-if)#switchport access vlan {vlan}
Slow response times - low throughput - runts and other input errors on the switch ports
The Drop adjacency

40. What is the name of the CEF engine that maintains routing information in software?
Switch#show running-config interface {interface}
Gigabit Ethernet over 1 pair 50 or 62.5 micron MMF (850 nm laser)
The Layer 3 engine
Gigabit Interface Converter (GBIC) or Small Form factor Pluggable (SFP)

41. What RJ-45 pins must be swapped in a Category 5 UTP crossover cable for Gigabit Ethernet?
Layer 2 source and destination MAC addresses; Layer 3 Time-To-Live (TTL) value and header checksum
Switch(config)#errdisable detect cause pagp-flap
Switch#show adjacency [{interface}] [summary | detail]
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

42. 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)
Switch(config-if)#switchport mode access
Distributed CEF (dCEF)
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

43. What is 10GBASE-LR/LW?
10 Gigabit Ethernet over 9 micron SMF (1310 nm serial laser)
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
Source MAC address; Port of arrival; VLAN; Time stamp
CEF punt

44. What is IEEE?
10GbE operates only at full duplex
Institute of Electrical and Electronics Engineers
A switch port that has been shut down automatically due to a serious error condition
15 metres

45. What are the letters used with 10GBASE-X two-letter suffixes to specify the transceiver wavelengths?
S = Short; L = Long; E = Extra-long
Mask bits set to 1 for Value bits of interest and 0 for Value bits that don't matter
Switch#show interfaces status err-disabled
The Null adjacency

46. What is the original standard for Ethernet (10 Mbps)?
SC fibre optic or RJ-45 UTP
IEEE 802.3
Cisco Express Forwarding
Switch(config)#errdisable detect cause vmps

47. When should CEF be disabled?
Compiling Access Control Entries (ACE) into the TCAM table
Only temporarily for debugging purposes
Mask bits set to 1 for Value bits of interest and 0 for Value bits that don't matter
40 km

48. What is the name of physical network segment where data packets can collide with one another when being sent?
Switch(config-if)#no switchport
Collision domain
1000BASE-CX - 1000BASE-T - 1000-BASE-SX - 1000-BASE-LX/LH and 1000-BASE-ZX
Switch(config)#errdisable detect cause dhcp-rate-limit

49. What tables are maintained by the CEF Layer 3 engine?
The Layer 3 engine
R = LAN PHY; W = WAN PHY
Routing table and ARP table
Cabling specifications for Gigabit Ethernet

50. What is the name of a Layer 3 logical interface on a switch that represents an entire VLAN?
Switch(config)#errdisable detect cause udld
SVI
Switch#show errdisable recovery
Switch(config)#define interface-range {macro-name} {type} {module}/{number} [- {number}] [ - {type} {module}/{number} ...]