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Full Discussion: regarding net
Top Forums Programming regarding net Post 302096378 by Corona688 on Wednesday 15th of November 2006 09:47:14 AM
Old 11-15-2006
Ping your own gateway? Which? A server system could easily have more than one network card and complex network routing. Pinging some other site lets the system handle the choice of routes for you. Some will block it, yes, so just pick one that does not!

Try system() instead of popen(). The return value will be zero if connected to the net, nonzero if not. Also investigate the options for ping to limit the number of pings to one, and change the timeout to your preference:
Code:
if(system("ping -c 1 -w 1 yahoo.com > /dev/null 2> /dev/null") != 0)
  fprintf(stderr,"Net is down!\n");
else
  fprintf(stderr,"Net is up\n");

The file redirection just prevents ping from polluting the output with unnecessary stuff.

You could also open a network socket to, say, yahoo.com port 80. If you can do that, the net is up. Not as easy to configure timeouts for that though.

Last edited by Corona688; 11-15-2006 at 10:55 AM..
 

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Smokeping_probes_OpenSSHJunOSPing(3)				     SmokePing				      Smokeping_probes_OpenSSHJunOSPing(3)

NAME
Smokeping::probes::OpenSSHJunOSPing - Juniper SSH JunOS Probe for SmokePing SYNOPSIS
*** Probes *** +OpenSSHJunOSPing forks = 5 offset = 50% packetsize = 100 step = 300 timeout = 15 # The following variables can be overridden in each target section junospass = password # mandatory junosuser = user # mandatory pings = 5 psource = 192.168.2.129 source = 192.168.2.1 # mandatory # [...] *** Targets *** probe = OpenSSHJunOSPing # if this should be the default probe # [...] + mytarget # probe = OpenSSHJunOSPing # if the default probe is something else host = my.host junospass = password # mandatory junosuser = user # mandatory pings = 5 psource = 192.168.2.129 source = 192.168.2.1 # mandatory DESCRIPTION
Connect to Juniper JunOS via OpenSSH to run ping commands. This probe uses the "extended ping" of the Juniper JunOS. You have the option to specify which interface the ping is sourced from as well. VARIABLES
Supported probe-specific variables: forks Run this many concurrent processes at maximum Example value: 5 Default value: 5 offset If you run many probes concurrently you may want to prevent them from hitting your network all at the same time. Using the probe- specific offset parameter you can change the point in time when each probe will be run. Offset is specified in % of total interval, or alternatively as 'random', and the offset from the 'General' section is used if nothing is specified here. Note that this does NOT influence the rrds itself, it is just a matter of when data acqusition is initiated. (This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.) Example value: 50% packetsize The (optional) packetsize option lets you configure the packetsize for the pings sent. Default value: 100 step Duration of the base interval that this probe should use, if different from the one specified in the 'Database' section. Note that the step in the RRD files is fixed when they are originally generated, and if you change the step parameter afterwards, you'll have to delete the old RRD files or somehow convert them. (This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.) Example value: 300 timeout How long a single 'ping' takes at maximum Example value: 15 Default value: 5 Supported target-specific variables: junospass The junospass option allows you to specify the password for the username specified with the option junosuser. Example value: password This setting is mandatory. junosuser The junosuser option allows you to specify a username that has ping capability on the JunOS Device. Example value: user This setting is mandatory. pings How many pings should be sent to each target, if different from the global value specified in the Database section. Note that the number of pings in the RRD files is fixed when they are originally generated, and if you change this parameter afterwards, you'll have to delete the old RRD files or somehow convert them. Example value: 5 psource The (optional) psource option specifies an alternate IP address or Interface from which you wish to source your pings from. Routers can have many many IP addresses, and interfaces. When you ping from a router you have the ability to choose which interface and/or which IP address the ping is sourced from. Specifying an IP/interface does not necessarily specify the interface from which the ping will leave, but will specify which address the packet(s) appear to come from. If this option is left out the JunOS Device will source the packet automatically based on routing and/or metrics. If this doesn't make sense to you then just leave it out. Example value: 192.168.2.129 source The source option specifies the JunOS device that is going to run the ping commands. This address will be used for the ssh connection. Example value: 192.168.2.1 This setting is mandatory. AUTHORS
Tobias Oetiker lttobi@oetiker.chgt based on Smokeping::probes::TelnetJunOSPing by S H A N ltshanali@yahoo.comgt. NOTES
JunOS configuration The JunOS device should have a username/password configured, as well as the ability to connect to the VTY(s). Make sure to connect to the remote host once from the commmand line as the user who is running smokeping. On the first connect ssh will ask to add the new host to its known_hosts file. This will not happen automatically so the script will fail to login until the ssh key of your juniper box is in the known_hosts file. Some JunOS devices have a maximum of 5 VTYs available, so be careful not to hit a limit with the 'forks' variable. Requirements This module requires the Net::OpenSSH and IO::Pty. 2.6.8 2013-03-17 Smokeping_probes_OpenSSHJunOSPing(3)
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