In my application I am pinging a server and waiting for a response. I am using this to determine whether the server is available and responsive or not.
Is this a reliable way of determining availability? I assume a firewall could be filtering icmp traffic... Are there any other drawbacks? Is there a more reliable method?
Just a quick sanity check here.
Can you ping a specific port of a machine, and if so, can you provide an example?
I'm looking for something like ping ip address portNum.
I am trying to write a script that lists all the hosts on my LAN (there a about 20 of them) and writes the ping status next to each host. I have the DHCP leases file, so I have all the IPs (say, 10.0.0.1, 10.0.0.2, etc.), all I need is the ping status for each host.
So, my script launches a single ping for each host:
ping -c 1 10.0.0.1
Unfortunately, when a host is offline, the ping takes a long time to timeout. I checked man ping, there seem to be two options to set the timeout delay: -w deadline and -W timeout. I think I'm interested in the latter.
So I tried this:
ping -c 1 -W 1 10.0.0.1
But waiting one second per offline host is still too long. I tried to set it to below a second, but it does not seem to take the parameter into account at all:
ping -c 1 -W 0.1 10.0.0.1 # timeout option is ignored, apparently
Is there a way to set the timeout to a lower value? If not, are there any alternatives?
Edit
ping -b for example).Edit #2
I accepted the fping solution (thanks for all the other answers). This command does exactly what I was looking for:
fping -c1 -t500 10.0.0.1 10.0.0.2 10.0.0.3 10.0.0.4
This command takes at most 500ms to complete, and gives me the ping status of all the hosts at once:
10.0.0.1 : [0], 84 bytes, 5.71 ms (5.71 avg, 0% loss)
10.0.0.2 : [0], 84 bytes, 7.95 ms (7.95 avg, 0% loss)
10.0.0.3 : [0], 84 bytes, 16.1 ms (16.1 avg, 0% loss)
10.0.0.4 : [0], 84 bytes, 48.0 ms (48.0 avg, 0% loss)
10.0.0.1 : xmt/rcv/%loss = 1/1/0%, min/avg/max = 5.71/5.71/5.71
10.0.0.2 : xmt/rcv/%loss = 1/1/0%, min/avg/max = 7.95/7.95/7.95
10.0.0.3 : xmt/rcv/%loss = 1/1/0%, min/avg/max = 16.1/16.1/16.1
10.0.0.4 : xmt/rcv/%loss = 1/1/0%, min/avg/max = 48.0/48.0/48.0
On Debian Lenny, installation is trivial:
aptitude update
aptitude install fping
How can I ping a certain address and when found, stop pinging.
I want to use it in a bash script, so when the host is starting up, the script keeps on pinging and from the moment the host is available, the script continues...
We get the message “TTL expired in transit” when we try to ping to a server in a different network segment. When we run tracert, 4 ip addresses repeat themselves indefinitely:
14 60 ms 59 ms 60 ms xxx.xxx.xxx.2
15 83 ms 81 ms 82 ms xxx.xxx.xxx.128
16 75 ms 80 ms 81 ms xxx.xxx.xxx.249
17 81 ms 78 ms 80 ms xxx.xxx.xxx.250
18 82 ms 80 ms 77 ms xxx.xxx.xxx.2
19 102 ms 101 ms 100 ms xxx.xxx.xxx.128
20 101 ms 100 ms 98 ms xxx.xxx.xxx.249
21 97 ms 98 ms 99 ms xxx.xxx.xxx.250
...
What are the basic steps for troubleshooting this error?