On the source end, the value of the Output:echo field increases normally but the value of the Input:echo field does not increase.If the following conditions are all met, it indicates that the source end sends Request packets but does not receive any Response packet, and the destination end does not receive the Request packets. Perform a ping operation, and then run the display icmp statistics command again to view statistics about ICMP packets.ДЄccording to the numbers of sent and received ICMP packets, you can locate the direction in which the fault occurs: If the number of ICMP packets does not increase, it indicates that the card or the device does not receive other ICMP packets such as ICMP packets sent from the NMS. Run the display icmp statistics command on the destination end to view statistics about packets on a specified interface board. Run the display icmp statistics command on the source end to view statistics about packets on the SRU. If this condition is not met, you need to specify the directly connected interface as the outbound interface. If a broadcast interface such as an Ethernet interface is specified as an outbound interface, the destination address to be pinged must be the address of the directly connected interface. Route Port, The Maximum Transmit Unit is 1500Д¬heck whether the ping -i command is run, that is, whether an outbound interface is specified. You can run the following command to view the MTU of an interface: display interface gigabitethernet 1/0/0 GigabitEthernet1/0/0 current state : UPДescription:HUAWEI, AR Series, GigabitEthernet1/0/0 Interface If the MTU is smaller than the size of the ping packet, packet loss will occur, in which case, you need to change the size of the ping packet to a value smaller than the MTU or change the ping operation. In this case, check whether the MTU of the outbound interface along the path is smaller than the size of the ping packet. If this command is run, it indicates that packet fragmentation is not supported.

Check whether the ping operation is properly performed.Д¬heck whether the ping -f command is run.

The parameter -vpn-instance vpn-name specifies the VPN instance to which the pinged destination address belongs. To ping a private network address from a PE, you need to run the ping -vpn-instance vpn-name destination-address command. Check the device and link status and clear the fault. If the ping operation can succeed only after -t is increased to a very long value, there is a possibility that a fault occurs on the device or link. To solve this problem, increase the value of -t. If the preceding information is displayed, it indicates that the ping failure occurs because the configured link transmission delay is shorter than the actual delay.

PING 10.1.1.1: 56 data bytes, press CTRL_C to breakД®rror: Sequence number = 1 is less than the correct = 2! If ping packet loss occurs because the configured link transmission delay is shorter than the actual delay, the following information is displayed: ping -v -t 1 10.1.1.1 Therefore, you can specify proper values for -t and -v to check whether the ping failure is caused by a long link transmission delay. The ping operation succeeds if a Response packet is received within a specified period, and the ping operation fails if no Response packet is received within the specified period.

Ping transmit failure