16 Replies Latest reply on Jan 25, 2012 12:45 PM by d09h

    Why does NPM store the IP rather than use DNS

    dan_reeder@harte-hanks.com

      Why does NPM store the IP rather than use DNS for polling?  It's not a big deal but anytime we change an IP, we have to go into Orion to update the node with the new IP.

        • Re: Why does NPM store the IP rather than use DNS
          sean.martinez

          Orion uses the IP Address so it can continue to Poll even if the DNS Server goes down. You can have Orion update the IP Address based on the DNS Name by going into Manager Nodes> Edit Properties, and select the checkbox for Dynamic IP Address (DHCP or BOOTP).

           

          Please make sure that the Node does resolve via DNS lookup on the Orion Server by going into Command Prompt and running a quick ping on the Hostname and that the IP Address is correct as well. This is to ensure that the Orion Server is pointing to the Correct DNS Server.

            • Re: Why does NPM store the IP rather than use DNS
              joeygartin
              How often does it query DNS?  Everytime it does a ping?  Hopefully not.  Is there a setting for how often?

              Thank you!
              • Re: Why does NPM store the IP rather than use DNS
                lateforwork2


                Orion uses the IP Address so it can continue to Poll even if the DNS Server goes down. You can have Orion update the IP Address based on the DNS Name by going into Manager Nodes> Edit Properties, and select the checkbox for Dynamic IP Address (DHCP or BOOTP).

                 



                 

                Yes, but you cannot edit multiple nodes and Select "Dynamic IP" .....this is a horrible pain when you want to discover 400 nodes and have to edit each, individually.

                Please, please, please fix this.

                  • Re: Why does NPM store the IP rather than use DNS
                    pacetti


                    Yes, but you cannot edit multiple nodes and Select "Dynamic IP" .....this is a horrible pain when you want to discover 400 nodes and have to edit each, individually.

                    Please, please, please fix this.

                     



                    Marked for PM review.

                      • Re: Why does NPM store the IP rather than use DNS
                        Lt.Ripley

                        I use this feature as well but it does not always work for us.  We have a support call open with SolarWinds right now because we can't follow cluster resources that are DHCP instead of static.  They are detected initially with correct info, but then the IP reverts to one of the cluster host nodes instead of the resource. 

                        • Re: Why does NPM store the IP rather than use DNS
                          lateforwork2

                          This was marked for PM Review, but I never heard anything more.  Has a fix for this been implemented? Reviewed by PM? Anything?  As with most of my questions, it gets marked, or promised to review and I never hear anything ever again.  The follow ups seem to be severely lacking at Solarwinds.  

                          Tx.

                            • Re: Why does NPM store the IP rather than use DNS
                              joeygartin

                              If someone can point out the column (too busy to really look now) then we can do a SQL update on Nodes

                               

                              Update TABLENAME

                              SET columnName (what is the column and on what table) = 1 (or 0, checkboxes are usually 1 or 0 only) WHERE NodeID IN (put your group of NodeIds in here);

                               

                              If I wanted to update 100s of nodes at once to use Dynamic then I would do something like this OR leave the WHERE part out completely and ALL Nodes would be updated.  It is a matter of finding the ColumnName (most likely in the Nodes Table???) and figuring out which is which (dynamic = 0 OR 1).

                               

                              Two cents...

                                • Re: Why does NPM store the IP rather than use DNS
                                  sean.martinez

                                  How often does it query DNS? 

                                  If the Node is set to DHCP, I believe that we will resolve via Reverse DNS for Every Poll, so yes every 2 minutes. We have it function this way since some customers have rediscoveries are set as far out as several Days, and this would reduce Polling the wrong Node for availability.

                                   

                                  Is there a setting for how often? 

                                  No there is not.

                                   

                                  How do I update Nodes be selected to DHCP? 

                                  For all Nodes:

                                  Update Nodes Set DynamicIP='1'

                                   

                                  For a Group of Nodes based on the IP Address:

                                  Update Nodes Set DynamicIP='1' where IP_Address Like '10.10.1.%'

                                    • Re: Why does NPM store the IP rather than use DNS
                                      d09h

                                      For an external node monitored by node name and not IP, is there a way to alert when that IP changes?  What I thought would work has not (despite the resolved IP changing almost daily):

                                       

                                      The "Last 25 events" resource for the node shows

                                      "IP address of <I've removed hostname> changed from <I've removed this IP address> to <I've removed this IP address too>."

                                      The IP address is definitely changing and NPM sees it--every hour or two.  Yet I don't see an active alert.

                                        • Re: Why does NPM store the IP rather than use DNS
                                          d09h

                                          I did as suggested in an earlier post and now get alerts--albeit alerts with broken SQL syntax:

                                           

                                          "disable the reverse DNS lookup in Orion (in web console | Settings | Polling Settings | uncheck Perform reverse DNS lookup | Submit)"

                                           

                                          I now get a message stating the node name and that is has changed and then

                                           

                                          MACRO SQL ERROR - Incorrect syntax near '<first two octets of IP address removed>'.

                                           

                                           

                                           

                                          Can anyone suggest a SQL statement that would work here?  It must have been generate by Alert Manager, as I can't even spell SLQ.

                                          • Re: Why does NPM store the IP rather than use DNS
                                            d09h

                                            I did as suggested in an earlier post and now get alerts--albeit alerts with broken SQL syntax:


                                            "disable the reverse DNS lookup in Orion (in web console | Settings | Polling Settings | uncheck Perform reverse DNS lookup | Submit)"


                                            I now get a message stating the node name and that is has changed and then


                                            MACRO SQL ERROR - Incorrect syntax near '<first two octets of IP address removed>'.




                                            Can anyone suggest a SQL statement that would work here?  It must have been generate by Alert Manager, as I can't even spell SLQ.

                                              • Re: Why does NPM store the IP rather than use DNS
                                                d09h

                                                 

                                                yields alert emails that look like this:

                                                  • Re: Why does NPM store the IP rather than use DNS
                                                    DanielleH

                                                    d09h--

                                                    Can you try posting your screen shot again?

                                                      • Re: Why does NPM store the IP rather than use DNS
                                                        d09h

                                                        Orion has been seeing the address change of this node (first image).  I'm interested in seeing the IP changes.  Mostly when the hostname fails to resolve, but knowing the last working IP is helpful too.  It may be that the failure to resolve message will be to my liking...that condition just has not happened yet during the few days I've had this alert set up.  As the URL being monitored is integral to PKI implementation and SSL VPN connectivity, the inability to resolve the hostname is our clue to set an OSCP URL with an IP until DNS resolution begins working again.  Those things happen beyond my network edge.  This alert will allow me to change my OCSP URL before too many VPN users are effected.

                                                        When the OCSP hostname actually fails to resolve, I'll know how that event will look in Orion and will modify my alert and email to state that the hostname could not be resolved.  That's the ultimate goal.

                                                         

                                                         

                                                        Any idea how to make the message actually correctly present the IP address?  As in my image above, the email I receive does not show the email address--it shows a SQL error.  That's my main question at this point.

                                    • Re: Why does NPM store the IP rather than use DNS
                                      Lt.Ripley

                                      To resolve the majority of our issues, we were instructed to disable the reverse DNS lookup in Orion (in web console | Settings | Polling Settings | uncheck Perform reverse DNS lookup | Submit). 

                                      Most of our Windows hosts are using DHCP and the few that are still static are set to be changed this year.  We too have had to change the setting directly in SQL to update them all at once.  Since our Unix boxes still use static IP assignments, the exact query we run in SQL Server Mgmt Studio against the NetPerfmon database is:

                                      update Nodes set DynamicIP =1 where Vendor = 'Windows'

                                      I ran this on a small group of ~100 nodes using something other than 'vendor', just to ensure there were no adverse effects and all went well.  I've also tested setting Windows nodes that currently have static IPs to DHCP and we've had no issues there either.

                                      With the reverse DNS lookup disabled and the nodes set to DHCP, we've been far more successful in tracking nodes and/or clustered resources via name instead of IP.  For the problematic nodes, SolarWinds support came up with an additional step to resolve, detailed below.

                                      Our recurring problem was not following Server 2008 clusters using DHCP'd cluster resources.  When our DNS records have multiple entries, Orion would update the resource IP to the same one as its host node, which is completely separate.  Orion wasn't doing anything wrong - our DNS records are at fault, but we still needed a way to resolve this, especially since DNS records are not managed by our group.

                                      One of our nightly reports checks Orion for duplicate IP addresses so we set up an alert when duplicate IP's are found.  Then to resolve, we again need to go into SQL Server Mgmt Studio, and run the following queries against the NetPerfMon database:

                                      select * FROM Nodes where IP_Address = 'x.x.x.x'

                                      The query results then show both the host node and the virtual cluster resource with the NodeID number field. To fix within the database, we then run:

                                      update Nodes set DNS = 'resource-name.domain.com' where NodeID = xxxx

                                      Once this is set, that cluster resource will go back to it's proper IP during the next poll.  It all seems a bit convoluted but so far we have had 100% success in properly monitoring our DHCP'd resources now.  The updating nodes to DynamicIP=1 is a query we still need to run regularly just to ensure new discoveries are properly set.  Luckily, it's a simple query and extremely fast.