Linux Command Directory


Linux in a Nutshell

This directory of Linux commands is from Linux in a Nutshell, 5th Edition.

Click on any of the 687 commands below to get a description and list of available options. All links in the command summaries point to the online version of the book on Safari Bookshelf.

Buy it now, or read it online on Safari Bookshelf.



ping

ping [options] host

System administration command. Confirm that a remote host is online and responding. ping is intended for use in network testing, measurement, and management. Because of the load it can impose on the network, it is unwise to use ping during normal operations or from automated scripts.

Options

-a

Make ping audible. Beep each time response is received.

-A

Adapt to return interval of packets. Like -f ping, sends packets at approximately the rate at which they are received. This option may be used by an unprivileged user.

-b

Ping a broadcast address.

-B

Bind to original source address and do not change.

-c count

Stop after sending (and receiving) count ECHO_RESPONSE packets.

-f

Flood ping-output packets as fast as they come back or 100 times per second, whichever is greater. This can be very hard on a network and should be used with caution. Only a privileged user may use this option.

-i wait

Wait wait seconds between sending each packet. Default is to wait one second between each packet. This option is incompatible with the -f option.

-I name

Set source address to interface name. name may also be specified as an IP address.

-l preload

Send preload number of packets as fast as possible before falling into normal mode of behavior.

-L

If destination is a multicast address, suppress loopback.

-M hint

Specify Path MTU Discovery strategy. Accepted values are do, want, or dont.

-n

Numeric output only. No attempt will be made to look up symbolic names for host addresses.

-p digits

Specify up to 16 pad bytes to fill out packet sent. This is useful for diagnosing data-dependent problems in a network. digits are in hex. For example, -p ff will cause the sent packet to be filled with all 1s.

-q

Quiet output—nothing is displayed except the summary lines at startup time and when finished.

-Q tos

Set Quality of Service on ICMP datagrams.

-r

Bypass the normal routing tables and send directly to a host on an attached network.

-R

Set the IP record route option, which will store the route of the packet inside the IP header. The contents of the record route will be printed if the -v option is given, and will be set on return packets if the target host preserves the record route option across echoes or if the -l option is given.

-s packetsize

Specify number of data bytes to be sent. Default is 56, which translates into 64 ICMP data bytes when combined with the 8 bytes of ICMP header data.

-S size

Set send buffer (SNDBUF) size. The default is the size of one packet.

-t n

Set the IP Time to Live to n seconds.

-T option

Set IP timestamp options. Accepted option values are:

tsonly

Timestamps only.

tsandaddr

Timestamps and addresses.

tsprespec hosts

Timestamps with prespecified hops of one or more hosts.

-U

Use older ping behavior and print full user-to-user latency instead of network round-trip time.

-v

Verbose; list ICMP packets received other than ECHO_RESPONSE.

-V

Print version, then exit.

-w n

Exit ping after n seconds.

-W n

When waiting for a response, time out after n seconds.


More Linux resources from O'Reilly >>

Popular Topics

Browse Books & Videos

International Sites

O'Reilly China O'Reilly Germany O'Reilly Japan