Ping, tracert, and system debugging commands 1

Ping and tracert commands 1

ping· 1

tracert 4

display debugging· 6

 

Ping and tracert commands

ping

Use ping to verify whether the destination in an IP network is reachable, and to display the related statistics.

Syntax

ping [ ip ] [ -a source-ip | -c count | -f | -h ttl | -i interface-type interface-number | -m interval | -n | -p pad | -q | -r | -s packet-size | -t timeout | -tos tos | -v ] * host

Views

Any view

Default command level

0: Visit level

Parameters

ip: Supports IPv4 protocol. If this keyword is not provided, IPv4 is also supported.

-a source-ip: Specifies the source IP address of an ICMP echo request (ECHO-REQUEST). It must be an IP address configured on the device. If this parameter is not provided, the source IP address of an ICMP echo request is the primary IP address of the outbound interface of the request.

-c count: Specifies the number of times that an ICMP echo request is sent, which ranges from 1 to 4294967295 and defaults to 5.

-f: Discards packets larger than the MTU of a given interface, which means the ICMP echo request is not allowed to be fragmented.

-h ttl: Specifies the TTL value for an ICMP echo request, which ranges from 1 to 255 and defaults to 255.

-i interface-type interface-number: Specifies the ICMP echo request sending interface by its type and number. If this parameter is not provided, the ICMP echo request sending interface is determined by searching the routing table or forwarding table according to the destination IP address.

-m interval: Specifies the interval (in milliseconds) to send an ICMP echo request, which ranges from 1 to 65535 and defaults to 200.

·           If a response from the destination is received within the timeout time, the interval to send the next echo request equals the actual response period plus the value of interval.

·           If no response from the destination is received within the timeout time, the interval to send the next echo request equals the timeout value plus the value of interval.

-n: Disables domain name resolution for the host argument. When this keyword is not provided, if the host argument represents the host name of the destination, the device translates host into an address.

-p pad: Specifies the value of the pad field in an ICMP echo request, in hexadecimal format, 1 to 8 bits, in the range 0 to ffffffff. If the specified value is less than 8 bits, 0s are added in front of the value to extend it to 8 bits. For example, if pad is configured as 0x2f, then the packets are padded with 0x0000002f repeatedly to make the total length of the packet meet the requirements of the device. By default, the padded value starts from 0x01 up to 0xff, where another round starts again if necessary, like 0x010203…feff01….

-q: Presence of this keyword indicates that only statistics are displayed. Absence of this keyword indicates that all information is displayed.

-r: Records routing information. If this keyword is not provided, routes are not recorded.

-s packet-size: Specifies length (in bytes) of an ICMP echo request, which ranges from 20 to 8100 and defaults to 56.

-t timeout: Specifies the timeout value (in milliseconds) of an ICMP echo reply (ECHO-REPLY). If the source does not receive an ICMP echo reply within the timeout, it considers the ICMP echo reply timed out. The value ranges from 0 to 65535 and defaults to 2000.

-tos tos: Specifies the type of service (ToS) value of an echo request, which ranges from 0 to 255 and defaults to 0. Starting from 0, every four consecutive ToS values correspond to a DSCP priority value. Network devices use the DSCP value as a reference to determine the packet priority for transmission.

-v: Displays non ICMP echo reply received. If this keyword is not provided, the system does not display non ICMP echo reply.

host: IP address or host name (a string of 1 to 255 characters) of the destination.

Usage guidelines

With the ping command executed, the source sends an ICMP echo request to the destination:

·           If the destination name is unrecognizable, the system outputs "Error:  Ping: Unknown host host-name".

·           If the source receives an ICMP echo reply from the destination within the timeout, the system outputs the related information of the reply.

·           If the source does not receive an ICMP echo reply from the destination within the timeout, the system outputs "Request time out".

To use the name of the destination host to perform the ping operation, you must configure the Domain Name System (DNS) on the device first. Otherwise, the ping operation fails. For more information about DNS, see Layer 3—IP Services Configuration Guide.

To abort the ping operation during the execution of the command, press Ctrl+C.

Examples

# Examine whether the device with an IP address of 1.1.2.2 is reachable.

<Sysname> ping 1.1.2.2

  PING 1.1.2.2: 56  data bytes, press CTRL_C to break

    Reply from 1.1.2.2: bytes=56 Sequence=1 ttl=254 time=205 ms

    Reply from 1.1.2.2: bytes=56 Sequence=2 ttl=254 time=1 ms

    Reply from 1.1.2.2: bytes=56 Sequence=3 ttl=254 time=1 ms

    Reply from 1.1.2.2: bytes=56 Sequence=4 ttl=254 time=1 ms

    Reply from 1.1.2.2: bytes=56 Sequence=5 ttl=254 time=1 ms

 

  --- 1.1.2.2 ping statistics ---

    5 packet(s) transmitted

    5 packet(s) received

    0.00% packet loss

    round-trip min/avg/max = 1/41/205 ms

The output shows the following:

·           The destination is reachable.

·           All ICMP echo requests sent by the source have got responses.

·           The minimum time, average time, and maximum time for the packet’s roundtrip time are 1 ms, 41 ms, and 205 ms respectively.

# Examine whether the device with an IP address of 1.1.2.2 is reachable. Only the results are displayed.

<Sysname> ping -q 1.1.2.2

  PING 1.1.2.2: 56  data bytes, press CTRL_C to break

 

  --- 1.1.2.2 ping statistics ---

    5 packet(s) transmitted

    4 packet(s) received

    20.00% packet loss

    round-trip min/avg/max = 1/12/29 ms

# Examine whether the device with an IP address of 1.1.2.2 is reachable. The route information is displayed.

<Sysname> ping -r 1.1.2.2

  PING 1.1.2.2: 56  data bytes, press CTRL_C to break

    Reply from 1.1.2.2: bytes=56 Sequence=1 ttl=254 time=53 ms

      Record Route:

         1.1.2.1

         1.1.2.2

         1.1.1.2

         1.1.1.1

    Reply from 1.1.2.2: bytes=56 Sequence=2 ttl=254 time=1 ms

      Record Route:

         1.1.2.1

         1.1.2.2

         1.1.1.2

         1.1.1.1

    Reply from 1.1.2.2: bytes=56 Sequence=3 ttl=254 time=1 ms

      Record Route:

         1.1.2.1

         1.1.2.2

         1.1.1.2

         1.1.1.1

    Reply from 1.1.2.2: bytes=56 Sequence=4 ttl=254 time=1 ms

      Record Route:

         1.1.2.1

         1.1.2.2

         1.1.1.2

         1.1.1.1

    Reply from 1.1.2.2: bytes=56 Sequence=5 ttl=254 time=1 ms

      Record Route:

         1.1.2.1

         1.1.2.2

         1.1.1.2

         1.1.1.1

 

  --- 1.1.2.2 ping statistics ---

    5 packet(s) transmitted

    5 packet(s) received

    0.00% packet loss

    round-trip min/avg/max = 1/11/53 ms

The output shows the following information:

·           The destination is reachable.

·           The route is 1.1.1.1 <-> {1.1.1.2; 1.1.2.1} <-> 1.1.2.2.

Table 1 Command output

Field	Description
PING 1.1.2.2	Examine whether the device with IP address 1.1.2.2 is reachable.
56  data bytes	Number of data bytes in each ICMP echo request.
press CTRL_C to break	During the execution of the command, you can press Ctrl+C to abort the ping operation.
Reply from 1.1.2.2 : bytes=56 Sequence=1 ttl=255 time=1 ms	Received the ICMP reply from the device whose IP address is 1.1.2.2. If no reply is received during the timeout period, "Request time out" is displayed. ·       bytes—Number of data bytes in the ICMP reply. ·       Sequence—Packet sequence, used to determine whether a segment is lost, disordered or repeated. ·       ttl—TTL value in the ICMP reply. ·       time—Response time.
Record Route	Routers through which the ICMP echo request passed. They are displayed in inversed order. The router with a smaller distance to the destination is displayed first.
--- 1.1.2.2 ping statistics ---	Statistics on data received and sent in the ping operation.
5 packet(s) transmitted	Number of ICMP echo requests sent.
5 packet(s) received	Number of ICMP echo requests received.
0.00% packet loss	Percentage of packets not responded to the total packets sent.
round-trip min/avg/max = 0/4/20 ms	Minimum/average/maximum response time, in ms. The field is not available for failed ping attempts.

 

tracert

Use tracert to trace the path the packets traverse from source to destination.

Syntax

tracert [ -a source-ip | -f first-ttl | -m max-ttl | -p port | -q packet-number | -tos tos | -w timeout ] * host

Views

Any view

Default command level

0: Visit level

Parameters

-a source-ip: Specifies the source IP address of a tracert packet. It must be a legal IP address configured on the device. If this parameter is not provided, the source IP address of an ICMP echo request is the primary IP address of the outbound interface of the tracert packet.

-f first-ttl: Specifies the first TTL, or, the allowed number of hops for the first packet. It ranges from 1 to 255 and defaults to 1, and must be less than the maximum TTL.

-m max-ttl: Specifies the maximum TTL, or, the maximum allowed number of hops for a packet. It ranges from 1 to 255 and defaults to 30, and must be greater than the first TTL.

-p port: Specifies the UDP port number of the destination, which ranges from 1 to 65535 and defaults to 33434. You do not need to modify this parameter.

-q packet-number: Specifies the number of probe packets sent each time, which ranges from 1 to 65535 and defaults to 3.

-tos tos: Specifies the ToS value of a tracert packet, which ranges from 0 to 255 and defaults to 0. Starting from 0, every four consecutive ToS values correspond to a DSCP priority value. Network devices use the DSCP value as a reference to determine the packet priority for transmission.

-w timeout: Specifies the timeout time of the reply packet of a probe packet, which ranges from 1 to 65535 milliseconds and defaults to 5000 milliseconds.

host: IP address or host name (a string of 1 to 255 characters) of the destination.

Usage guidelines

Output from the tracert command includes IP addresses of all the Layer 3 devices the packets traverse from source to destination. Asterisks (* * *) are displayed if the device cannot reply with an ICMP error message (probably because the destination is unreachable or sending ICMP timeout/destination unreachable packets is disabled).

To abort the tracert operation during the execution of the command, press Ctrl+C.

Examples

# Display the path the packets traverse from source to destination with an IP address of 1.1.2.2.

<Sysname> tracert 1.1.2.2

 traceroute to 1.1.2.2(1.1.2.2) 30 hops max,40 bytes packet, press CTRL_C to break

 1  1.1.1.2 673 ms 425 ms 30 ms

 2  1.1.2.2 580 ms 470 ms 80 ms

Table 2 Command output

Field	Description
traceroute to 1.1.2.2(1.1.2.2)	Display the route the IP packets traverse from the current device to the device whose IP address is 1.1.2.2.
hops max	Maximum number of hops of the probe packets, which can be set through the -m keyword.
bytes packet	Number of bytes of a probe packet.
press CTRL_C to break	During the execution of the command, you can press Ctrl+C to abort the tracert operation.
1  1.1.1.2 673 ms 425 ms 30 ms	Probe result of the probe packets whose TTL is 1, including the IP address of the first hop and the roundtrip time of three probe packets. Number of packets that can be sent in each probe can be set through the -q keyword.

 

display debugging

Use display debugging to display enabled debugging functions.

Syntax

display debugging [ interface interface-type interface-number ] [ module-name ] [ | { begin | exclude | include } regular-expression ]

Views

Any view

Default command level

1: Monitor level

Parameters

interface interface-type interface-number: Displays the debugging settings of the specified interface, where interface-type interface-number represents the interface type and number.

module-name: Module name.

|: Filters command output by specifying a regular expression. For more information about regular expressions, see Fundamentals Configuration Guide.

begin: Displays the first line that matches the specified regular expression and all lines that follow.

exclude: Displays all lines that do not match the specified regular expression.

include: Displays all lines that match the specified regular expression.

regular-expression: Specifies a regular expression, a case-sensitive string of 1 to 256 characters.

Examples

# Display all enabled debugging functions.

<Sysname> display debugging

IP packet debugging is on

Related commands

debugging