Re: [Nagios-users] How to check Internet access and/or DNS?
On 24/01/06, Marc Haber [EMAIL PROTECTED] wrote: On a second thought, how do I check DNS? I mean, even with the Internet down, my local DNS servers probably can correctly serve DNS records for my local network which they're authoritative for. So, does it make sense to check the DNS servers once for an external host (like www.nagios.org) and once for an internal host, resulting in two services being checked on the DNS server? Just do checks for a few DNS entries - your ISP's website, your externally hosted website, your internal website, nagios.org... If most of these go down at the same time as your web check to google.com, you know there's something bad happening :) Brian. --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid3432bid#0486dat1642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] How to check Internet access and/or DNS?
On Jan 23, 2006, at 23:56, Marc Haber wrote: some services, most notably DNS, depend on the Internet to be available. I'd like to express this in Nagios configuration. I'd probably need to have a service Internet for that where my DNS service definitions could depend on to avoid DNS being reported down in case of an internet outage. Any idea how to do this elegantly? I don't find the idea of pinging my ISP's router at the national Internet Exchange Point very appealing. Configure the parents field in the host definition for the host running the service you're checking across the Internet. It's parent should be your boarder router. You'll need to make a host def. for that router, as well as a service to check on it (use the dummy service for that). With such a setup, there'll be no real periodic check of the router, but it will be ping'd if your across-the- Internet service fails, and you'll get just one notification (either router down or remote service unavailable). On a second thought, how do I check DNS? I mean, even with the Internet down, my local DNS servers probably can correctly serve DNS records for my local network which they're authoritative for. So, does it make sense to check the DNS servers once for an external host (like www.nagios.org) and once for an internal host, resulting in two services being checked on the DNS server? What do you do regarding DNS server checks? Well, you check the DNS with the check_dns plug-in, of course ;^) Seriously, though, it depends on your infrastructure. Generally speaking, I suggest that you use the plug-in to monitor all of _your_ nameservers and just assume that the only reason for the DNS outside of your organization to be down is an outage of your network, absolving you from having to monitor the DNS at large. You can monitor your Internet connection itself in many ways--paid service from the Internet, free from your home network, free from within your org. looking out (with lots of variation thereof). Pick what suits you best. -Guy --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid=103432bid=230486dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] How to check Internet access and/or DNS?
On Tue, 24 Jan 2006, Guy B. Purcell wrote: On Jan 23, 2006, at 23:56, Marc Haber wrote: some services, most notably DNS, depend on the Internet to be available. I'd like to express this in Nagios configuration. I'd probably need to have a service Internet for that where my DNS service definitions could depend on to avoid DNS being reported down in case of an internet outage. Any idea how to do this elegantly? I don't find the idea of pinging my ISP's router at the national Internet Exchange Point very appealing. Configure the parents field in the host definition for the host running the service you're checking across the Internet. It's parent should be your boarder router. You'll need to make a host def. for that router, as well as a service to check on it (use the dummy service for that). With such a setup, there'll be no real periodic check of the router, but it will be ping'd if your across-the- Internet service fails, and you'll get just one notification (either router down or remote service unavailable). There are propably a dozen ways or more to do this. My internet link is a fake host which has the IP adres of my DSL router. On it I have defined a check which will see if a tunnel is still active. (This tunnel is an accurate indication of my connectivity.) The IPv6 tunnel is similarly defined giving me some indication wether or not internet is available. On my to-do list is to write a passive check that will turn snmp traps for these tunnels into host down and host up events that I can feed to nagios. Hugo. -- I hate duplicates. Just reply to the relevant mailinglist. [EMAIL PROTECTED] http://hvdkooij.xs4all.nl/ Don't meddle in the affairs of magicians, for they are subtle and quick to anger. --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid=103432bid=230486dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] How to check Internet access and/or DNS?
On Wed, Jan 25, 2006 at 04:34:34PM +1300, Steve Shipway wrote: So many different ways to do this. We do it thusly. 1) Set up a host for your border router. 2) Within this, sefine a number of http check services that try to collect web pages from popular internet sites ( google, microsoft, ibm...). Disable notifications on them. 3) Use check_summary (from nagiosexchange.org) to define a service which is OK if any of the http check services are OK, and critical if they are all down. That's a quite neat idea. I like that. Thanks! Greetings Marc -- - Marc Haber | I don't trust Computers. They | Mailadresse im Header Mannheim, Germany | lose things.Winona Ryder | Fon: *49 621 72739834 Nordisch by Nature | How to make an American Quilt | Fax: *49 621 72739835 --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid=103432bid=230486dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
