A lot of us hear the word ping used a lot in gaming and when we are having network issues, but what exactly is ping?

ping

ping is a command line tool that is used to measure the round-trip time for messages sent from one computer to another. This is often used to test if there is a connection between your computer and a website.

Command Options
WindowsLinux
Option Description
-t Ping the specified host until stopped. To see statistics and continue – type Control-Break; To stop – type Control-C.
-a Resolve addresses to hostnames.
-n count Number of echo requests to send.
-l size Send buffer size.
-f Set Don’t Fragment flag in packet (IPv4-only).
-i TTL Time to Live.
-r count Record route for count hops (IPv4-only)
-s count Timestamp for count hops (IPv4-only).
-j host-list Loose source route along host-list (IPv4-only).
-k host-list Strict source route along host-list (IPv4-only).
-w timeout Timeout in milliseconds to wait for each reply.
-S srcaddr Source address to use.
-c compartment Routing compartment identifier.
-p Ping a Hyper-V Network Virtualization provider address.
-4 Force using IPv4.
-6 Force using IPv6.
Option Description
-a Audible ping.
-A Adaptive ping. Interpacket interval adapts to round-trip time, so that effectively not more than one (or more, if preload is set) unanswered probes present in the network. Minimal interval is 200msec for not super-user. On networks with low rtt this mode is essentially equivalent to flood mode.
-b Allow pinging a broadcast address.
-B Do not allow ping to change source address of probes. The address is bound to one selected when ping starts.
-c count Stop after sending count ECHO_REQUEST packets. With deadline option, ping waits for count ECHO_REPLY packets, until the timeout expires.
-d Set the SO_DEBUG option on the socket being used. Essentially, this socket option is not used by Linux kernel.
-F flow label Allocate and set 20 bit flow label on echo request packets. (Only ping6). If value is zero, kernel allocates random flow label.
-f Flood ping. For every ECHO_REQUEST sent a period ”.” is printed, while for ever ECHO_REPLY received a backspace is printed. This provides a rapid display of how many packets are being dropped. If interval is not given, it sets interval to zero and outputs packets as fast as they come back or one hundred times per second, whichever is more. Only the super-user may use this option with zero interval.
-i interval Wait interval seconds between sending each packet. The default is to wait for one second between each packet normally, or not to wait in flood mode. Only super-user may set interval to values less 0.2 seconds.
-I interface address Set source address to specified interface address. Argument may be numeric IP address or name of device. When pinging IPv6 link-local address this option is required.
-l preload If preload is specified, ping sends that many packets not waiting for reply. Only the super-user may select preload more than 3.
-L Suppress loopback of multicast packets. This flag only applies if the ping destination is a multicast address.
-n Numeric output only. No attempt will be made to lookup symbolic names for host addresses.
-Q tos Set Quality of Service -related bits in ICMP datagrams. tos can be either decimal or hex number. Traditionally (RFC1349), these have been interpreted as: 0 for reserved (currently being redefined as congestion control), 1-4 for Type of Service and 5-7 for Precedence. Possible settings for Type of Service are: minimal cost: 0x02, reliability: 0x04, throughput: 0x08, low delay: 0x10. Multiple TOS bits should not be set simultaneously. Possible settings for special Precedence range from priority (0x20) to net control (0xe0). You must be root (CAP_NET_ADMIN capability) to use Critical or higher precedence value. You cannot set bit 0x01 (reserved) unless ECN has been enabled in the kernel. In RFC2474, these fields has been redefined as 8-bit Differentiated Services (DS), consisting of: bits 0-1 of separate data (ECN will be used, here), and bits 2-7 of Differentiated Services Codepoint (DSCP).
-q Quiet output. Nothing is displayed except the summary lines at startup time and when finished.
-R Record route. Includes the RECORD_ROUTE option in the ECHO_REQUEST packet and displays the route buffer on returned packets. Note that the IP header is only large enough for nine such routes. Many hosts ignore or discard this option.
-r Bypass the normal routing tables and send directly to a host on an attached interface. If the host is not on a directly-attached network, an error is returned. This option can be used to ping a local host through an interface that has no route through it provided the option -I is also used.
-s packetsize Specifies the number of data bytes to be sent. The default is 56, which translates into 64 ICMP data bytes when combined with the 8 bytes of ICMP header data.
-S sndbuf Set socket sndbuf. If not specified, it is selected to buffer not more than one packet.
-t ttl Set the IP Time to Live.
-T timestamp option Set special IP timestamp options. timestamp option may be either tsonly (only timestamps), tsandaddr (timestamps and addresses) or tsprespec host1 [host2 [host3 [host4]]] (timestamp prespecified hops).
-M hint Select Path MTU Discovery strategy. hint may be either do (prohibit fragmentation, even local one), want (do PMTU discovery, fragment locally when packet size is large), or dont (do not set DF flag).
-U Print full user-to-user latency (the old behaviour). Normally ping prints network round trip time, which can be different f.e. due to DNS failures.
-v Verbose output.
-V Show version and exit.
-w deadline Specify a timeout, in seconds, before ping exits regardless of how many packets have been sent or received. In this case ping does not stop after count packet are sent, it waits either for deadline expire or until count probes are answered or for some error notification from network.
-W timeout Time to wait for a response, in seconds. The option affects only timeout in absense of any responses, otherwise ping waits for two RTTs.
Note: Linux uses ping and ping6 to distinuish between IPv4 and IPv6

Use Case

If you are having issues connecting to the internet many will try to test the issue by sending a ping request to a known working website. We will use google.com in this example.

If we run the command ping google.com we should get the following output:

Successful ping
Pinging google.com [172.217.5.78] with 32 bytes of data:

Reply from 172.217.5.78: bytes=32 time=22ms TTL=53

Reply from 172.217.5.78: bytes=32 time=26ms TTL=53

Reply from 172.217.5.78: bytes=32 time=23ms TTL=53

Reply from 172.217.5.78: bytes=32 time=68ms TTL=53

Ping statistics for 172.217.5.78:

   Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

    Minimum = 22ms, Maximum = 68ms, Average = 34ms

If all our packets get replies then we have a good connection. If some of them are lost it could mean that there is some network interference preventing a stable connection. If all of them are lost then we are looking at three different possible issues:

  1. The website is down.
  2. You are not connected to the internet.
  3. You are having DNS problems.

We can test number 3 by typing in the IP Address of the website you wish to ping. If you get no packets then the issue is not likely a DNS issue. If you receive your packets then we may be able to fix the issue by flushing our DNS Resolver Catch with ipconfig /flushdns. To learn more about ipconfig look at our article here.

Sometimes we need to know our IP Address or troubleshoot internet connection issues. How do we do that? Well we have a handy tool built into Windows, ipconfig.

ipconfig is a Windows command line utility and network troubleshooting tool. To access it you just need to open the windows command line by pressing start and typing in cmd.

ipconfig has many arguments and follows the syntax:

ipconfig /argument [adapter]

Arguments

Many command line programs can be given additional options called arguments. These arguments usually start with a /. Here is a list of all the arguments that ipconfig has:

Argument Description
/? Displays Help File
/all Display full configuration information
/release
/release6
Release the IP address for IPv4/IPv6 for specified addapter
/renew
/renew6
Renew the IPv4/IPv6 address for the specified addapter
/flushdns Purges the DNS Resolver cache
/registerdns Refreshes all DHCP leases and re-registers DNS names
/displaydns Display the contents of the DNS Resolver Cache
/showclassid
/showclassid6
Displays all the IPv4/IPv6 dhcp class IDs allowed for adapter
/setclassid
/setclassid6
Modifies the IPv4/IPv6 DHCP class id

With these commands you can find a lot out about your wireless and wireless connections. A lot of connectivity issues can be fixed simply by using /renew and /flushdns.

We will continue to cover command line programs in the future.