Ethernet Slot Time Example
2021年4月10日Register here: http://gg.gg/ozvd3
Use display ethernet statistics to display the Ethernet statistics.
*Slot Time Aviation
*Ethernet Slot Time Example DefinitionSyntax
The length of the slot time is given by the technical nature of the medium and network card construction, and it is 512 bit times for 10/100 Mbps Ethernet, and 4096 bit times for 1 Gbps Ethernet. It should be noted that the importance of the slot time is only related to collision handling. – Slot time: basic unit of timing for the protocol Equal to RxTx Turnaround Time + Channel Sensing Time + Propagation Delay + MAC processing time – Backoff timer: counts slots until station’s turn to transmit.display ethernet statisticsslot slot-numberViewsUser viewPredefined user rolesnetwork-adminnetwork-operatorParametersslot slot-number: Displays the Ethernet statistics on the specified IRF member device. The slot-number argument represents the ID of the IRF member device.Examples# Display the Ethernet statistics on IRF member 1.
Table 3: Command outputFieldDescriptionETH receive packet statisticsStatistics about the Ethernet packets received on the Ethernet interface module. TotalnumTotal number of received packets:
ETHIINum—Number of packets encapsulated by using Ethernet-II.
SNAPNum—Number of packets encapsulated by using SNAP.
RAWNum—Number of packets encapsulated by using RAW.
ISIS—Number of packets encapsulated by using IS-IS.
LLCNum—Number of packets encapsulated by using LLC.
UnknownNum—Number of packets encapsulated by using unknown methods.
ForwardNum—Number of packets forwarded at Layer 2 or sent to the CPU.
ARP—Number of ARP packets.
MPLS—Number of MPLS packets.
ISIS—Number of IS-IS packets.
ISIS2—Number of large 802.3/802.2 frames encapsulated by using IS-IS.
IP—Number of IP packets.ETH receive error statisticsStatistics about the error Ethernet packets in the outbound direction on the Ethernet interface module. Errors might be included in packets or occur during the receiving process. The items include:
NullPoint—Number of packets that include null pointers.
ErrIfindex—Number of packets that include incorrect interface indexes.
ErrIfcb—Number of packets that include incorrect interface control blocks.
IfShut—Number of packets that are being received when the interface is shut down.
ErrAnalyse—Number of packets that include packet parsing errors.
ErrSrcMAC—Number of packets that include incorrect source MAC addresses.
ErrHdrLen—Number of packets that include header length errors.ETH send packet statisticsStatistics about the Ethernet packets sent by the Ethernet interface module:
L3OutNum—Number of packets sent out of Layer 3 Ethernet interfaces.
VLANOutNum—Number of packets sent out of VLAN interfaces.
FastOutNum—Number of packets fast forwarded.
L2OutNum—Number of packets sent out of Layer 2 Ethernet interfaces.
MbufRelayNum—Number of packets transparently sent.ETH send error statisticsStatistics about the error Ethernet packets in the outbound direction on the Ethernet interface module:
NullMbuf—Number of packets with null pointers.
ErrAdjFwd—Number of packets with adjacency table errors.
ErrPrepend—Number of packets with extension errors.
ErrHdrLen—Number of packets with header length errors.
ErrPad—Number of packets with padding errors.
ErrQosTrs—Number of packets that failed to be sent by QoS.
ErrVLANTrs—Number of packets that failed to be sent in VLANs.
ErrEncap—Number of packets that failed to be sent due to link header encapsulation failures.
ErrTagVLAN—Number of packets that failed to be sent due to VLAN tag encapsulation failures.
IfShut—Number of packets that are being sent when the interface is shut down.
IfErr—Number of packets with incorrect outgoing interfaces.
* Related Questions & Answers
*Selected ReadingComputer EngineeringComputer NetworkMCA
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is a network protocol for carrier transmission that operates in the Medium Access Control (MAC) layer. It senses or listens whether the shared channel for transmission is busy or not, and defers transmissions until the channel is free.
When more than one stations send their frames simultaneously, collision occurs. Back-off algorithm is a collision resolution mechanism which is commonly used to schedule retransmissions after collisions in Ethernet. The waiting time that a station waits before attempting retransmission of the frame is called as back off time.Algorithm of CSMA/CD
Step 1) When a frame is ready, the transmitting station checks whether the channel is idle or busy.
Step 2) If the channel is busy, the station waits until the channel becomes idle.
Step 3) If the channel is idle, the station starts transmitting and continually monitors the channel to detect collision.
Step 4) If a collision is detected, the station starts the binary exponential backoff algorithm.
Step 5) The station resets the retransmission counters and completes frame transmission.Binary Exponential Backoff Algorithm in case of Collision
Step 1) The station continues transmission of the current frame for a specified time along with a jam signal, to ensure that all the other stations detect collision.Slot Time Aviation
Step 2) The station increments the retransmission counter, c, that denote the number of collisions.
Step 3) The station selects a random number of slot times in the range 0 and 2c – 1. For example, after the first collision (i.e. c = 1), the station will wait for either 0 or 1 slot times. After the second collision (i.e. c = 2), the station will wait anything between 0 to 3 slot times. After the third collision (i.e. c = 3), the station will wait anything between 0 to 7 slot times, and so forth.
Step 4) If the station selects a number
Use display ethernet statistics to display the Ethernet statistics.
*Slot Time Aviation
*Ethernet Slot Time Example DefinitionSyntax
The length of the slot time is given by the technical nature of the medium and network card construction, and it is 512 bit times for 10/100 Mbps Ethernet, and 4096 bit times for 1 Gbps Ethernet. It should be noted that the importance of the slot time is only related to collision handling. – Slot time: basic unit of timing for the protocol Equal to RxTx Turnaround Time + Channel Sensing Time + Propagation Delay + MAC processing time – Backoff timer: counts slots until station’s turn to transmit.display ethernet statisticsslot slot-numberViewsUser viewPredefined user rolesnetwork-adminnetwork-operatorParametersslot slot-number: Displays the Ethernet statistics on the specified IRF member device. The slot-number argument represents the ID of the IRF member device.Examples# Display the Ethernet statistics on IRF member 1.
Table 3: Command outputFieldDescriptionETH receive packet statisticsStatistics about the Ethernet packets received on the Ethernet interface module. TotalnumTotal number of received packets:
ETHIINum—Number of packets encapsulated by using Ethernet-II.
SNAPNum—Number of packets encapsulated by using SNAP.
RAWNum—Number of packets encapsulated by using RAW.
ISIS—Number of packets encapsulated by using IS-IS.
LLCNum—Number of packets encapsulated by using LLC.
UnknownNum—Number of packets encapsulated by using unknown methods.
ForwardNum—Number of packets forwarded at Layer 2 or sent to the CPU.
ARP—Number of ARP packets.
MPLS—Number of MPLS packets.
ISIS—Number of IS-IS packets.
ISIS2—Number of large 802.3/802.2 frames encapsulated by using IS-IS.
IP—Number of IP packets.ETH receive error statisticsStatistics about the error Ethernet packets in the outbound direction on the Ethernet interface module. Errors might be included in packets or occur during the receiving process. The items include:
NullPoint—Number of packets that include null pointers.
ErrIfindex—Number of packets that include incorrect interface indexes.
ErrIfcb—Number of packets that include incorrect interface control blocks.
IfShut—Number of packets that are being received when the interface is shut down.
ErrAnalyse—Number of packets that include packet parsing errors.
ErrSrcMAC—Number of packets that include incorrect source MAC addresses.
ErrHdrLen—Number of packets that include header length errors.ETH send packet statisticsStatistics about the Ethernet packets sent by the Ethernet interface module:
L3OutNum—Number of packets sent out of Layer 3 Ethernet interfaces.
VLANOutNum—Number of packets sent out of VLAN interfaces.
FastOutNum—Number of packets fast forwarded.
L2OutNum—Number of packets sent out of Layer 2 Ethernet interfaces.
MbufRelayNum—Number of packets transparently sent.ETH send error statisticsStatistics about the error Ethernet packets in the outbound direction on the Ethernet interface module:
NullMbuf—Number of packets with null pointers.
ErrAdjFwd—Number of packets with adjacency table errors.
ErrPrepend—Number of packets with extension errors.
ErrHdrLen—Number of packets with header length errors.
ErrPad—Number of packets with padding errors.
ErrQosTrs—Number of packets that failed to be sent by QoS.
ErrVLANTrs—Number of packets that failed to be sent in VLANs.
ErrEncap—Number of packets that failed to be sent due to link header encapsulation failures.
ErrTagVLAN—Number of packets that failed to be sent due to VLAN tag encapsulation failures.
IfShut—Number of packets that are being sent when the interface is shut down.
IfErr—Number of packets with incorrect outgoing interfaces.
* Related Questions & Answers
*Selected ReadingComputer EngineeringComputer NetworkMCA
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is a network protocol for carrier transmission that operates in the Medium Access Control (MAC) layer. It senses or listens whether the shared channel for transmission is busy or not, and defers transmissions until the channel is free.
When more than one stations send their frames simultaneously, collision occurs. Back-off algorithm is a collision resolution mechanism which is commonly used to schedule retransmissions after collisions in Ethernet. The waiting time that a station waits before attempting retransmission of the frame is called as back off time.Algorithm of CSMA/CD
Step 1) When a frame is ready, the transmitting station checks whether the channel is idle or busy.
Step 2) If the channel is busy, the station waits until the channel becomes idle.
Step 3) If the channel is idle, the station starts transmitting and continually monitors the channel to detect collision.
Step 4) If a collision is detected, the station starts the binary exponential backoff algorithm.
Step 5) The station resets the retransmission counters and completes frame transmission.Binary Exponential Backoff Algorithm in case of Collision
Step 1) The station continues transmission of the current frame for a specified time along with a jam signal, to ensure that all the other stations detect collision.Slot Time Aviation
Step 2) The station increments the retransmission counter, c, that denote the number of collisions.
Step 3) The station selects a random number of slot times in the range 0 and 2c – 1. For example, after the first collision (i.e. c = 1), the station will wait for either 0 or 1 slot times. After the second collision (i.e. c = 2), the station will wait anything between 0 to 3 slot times. After the third collision (i.e. c = 3), the station will wait anything between 0 to 7 slot times, and so forth.
Step 4) If the station selects a number
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