The apropos
-Apropos is a command to search in the shell with a keyword, it will output all command related to the keyword
-Device-name:Current-position username$ apropos keyword; example with the command apropos archive, the shell will output tar, zip ecc...
apropos archive, the shell will output tar, zip ecc...
- apropos archive +apropos [-flag] keyword- +
-V (version) print version of the comnmand-h Help message how to use aproposThe ping command , is used to test connection between a local server/computer to a remote UNIX server.
- The ping command sends ICMP Echo Request packets to the remote server for accessing it.
- Each packet echoed back (via an ICMP Echo Response packet) is written to the shell output.
-Example; Device-name:Current-position username$ ping IP address; ping 192.168.3.2
-Device-name:Current-position username$ ping Server_name; ping yahoo.com
-The shell will output something like this: 64 bytes from 98.138.219.232: icmp_seq=0 ttl=49 time=144.781 ms for each packets that return (echoed back).
-Important to stop the ping command press control + c.
ping command, is used to test connection between a local server/computer to a remote UNIX server.
+ The ping command sends ICMP Echo Request packets to the remote server for accessing it.
+ Each packet echoed back (via an ICMP Echo Response packet) is written to the shell output.
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+
++ Usage: + +
Example: +
ping 192.168.3.2ping yahoo.comcontrol + c
- ping 192.168.3.2 + ping [-flag] server
-c send limited number of packets with ping -c (nr of packets) -n avoid dns lookup, avoid to lookup symbolic names for host addresses, so only numeric output -a get an audio warning, when the remote server comes online -b Allow pinging a broadcast address (broadcast network, is a network with many devices on it).-m (mark) tag the packets going out -b Allow pinging a broadcast address (broadcast network, is a network with many devices on it).-m (mark) tag the packets going out -f (Flood ping) For every ECHO_REQUEST sent (.) is printed,
for every ECHO_REPLY received, a backspace is printed.
- With this command you can easily understand how many packets are being dropped.-i (interval) set the interval between seending each packet (defaultn 1 second); only super-user can set interval values less than 0.2 seconds -I (interface-address) set souce adress to a specific interface adress, example the name of the device or IP. When pinging local adresses IPV6, is a needed flag
+ With this command you can easily understand how many packets are being dropped.-i (interval) set the interval between seending each packet (defaultn 1 second); only super-user can set interval values
+ less than 0.2 seconds -I (interface-address) set souce adress to a specific interface adress,
+ example the name of the device or IP. When pinging local adresses IPV6, is a needed flag -l (preload) ping send packets but don't wait for reply.(you need sudo = amministrator persmissions) -L Remove loopback of multicast packets -N (Nioption) send ICMpv6 request, instead of Echo requests ipv6 request Ipv6 adresses ipv4-all request Ipv4 adresses -L Remove loopback of multicast packets -N (Nioption) send ICMpv6 request, instead of Echo requests
+ ipv6 request Ipv6 adresses ipv4-all request Ipv4 adresses -p (pattern) specify up to 16 number to fill out the packets you send -D print timestamp (unix time + microseconds) in each line-q (Quiet output) Nothing displayed except the summary lines at the start and at the end.
Example: ping -q yahoo.com, shell Output initially PING yahoo.com (72.30.35.10): 56 data bytes, and nothig else
- until you stop the ping command, and the shell will display the stats. -R (Record route), displays the route buffer on the packets that include RECORD_ROUTE in the ECHO_REQUEST.-r bypass the normal routing in a directly-attached network -s (packetsize) Specifies the data bytes to send (default is 56 that + 8 byte of ICMP = 64 ICMP data bytes)
- Example: ping -s 33 yahoo.com; send packets of 33 + 8 ICMP = 41 bytes to yahoo.com. -t set IP time-to-live (set how long execute ping in seconds)
- Example: ping -t 3: the shell will ping yahoo.com for 3 seconds, and then stops.-U print full user-to-user latency (legacy ping behaviour).-v output verbose on output -V Display verion of command -w (deadline) Timeout in seconds of ping command, regardless of how many packets have been sent. -W (timeout), time waiting for a response from the server, if the server dosen't reply in the time set, the ping command will stop. -R (Record route), displays the route buffer on the packets that include RECORD_ROUTE in the ECHO_REQUEST.-r bypass the normal routing in a directly-attached network -s (packetsize) Specifies the data bytes to send (default is 56 that + 8 byte of ICMP = 64 ICMP data bytes) -t set IP time-to-live (set how long execute ping in seconds) -U print full user-to-user latency (legacy ping behaviour).-v output verbose on output -V Display verion of command -w (deadline) Timeout in seconds of ping command, regardless of how many packets have been sent. -W (timeout), time waiting for a response from the server, if the server dosen't reply in the time set, the ping command will stop.