11 Replies Latest reply on Jan 2, 2020 7:59 AM by David Heydecker

    Regarding scanning skipped IP

    Naveen Kumar N C
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      HI Team

       

      Is there any way we can scan skipped IP's for which end state is opt1st scan and reason as Optimizing on initial scan.

       

      Because these skipped IP's hosts are not in CMDB and we wanted it to scan successfully.

       

      Please assist.

        • 1. Re: Regarding scanning skipped IP
          Ketki Joshi

          Hi Naveen,

           

          Discovery system puts end state as "opt1st scan" when it identifies that device behind this current IP is same device which has been already scanned via other IP. This is the reason system decides to skip that IP. We call this as scan optimization.

           

          So the device behind this current IP should be present in CMDB as it has been already scanned via other IP.

           

          If you will go to DiscoveryAcess of the skipped IP, it will point you to inferred node for which it has been skipped. You can then search that inferred node in CMDB by its name.

           

          So mainly you do NOT need to scanned such skipped IPs.

           

          Thanks,

          Ketki Joshi

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          • 2. Re: Regarding scanning skipped IP
            Naveen Kumar N C

            Hi Joshi

             

            thanks for the quick assistance.

             

            I verified and found both inferred entity and host we are scanning is same.

            Also for other skipped IP's, we are getting same host name. that is strange

            When we looked at scanned result of inferred node it list several IP's with many skipped and one success..actually those are different hosts but listing under skipped.

            When verified in CMDB we are not getting even inferred node also, that's the concern.

            • 3. Re: Regarding scanning skipped IP
              Naveen Kumar N C

              Hi Joshi

              Let me reiterate our case.

               

              We are scanning ADDM cluster members. which has 3 members A,B,C

               

              A is getting scanned and is in CMDB.

              When scanned B and C its getting skipped. When looked at discovery access page of B and C, getting same hostname under inferred node as B & C respectively.

              But B & C not exist in CMDB.

               

              But when looked at scan result of A, we are getting IP of A is success and IP's of host B&C are skipped.

              • 4. Re: Regarding scanning skipped IP
                Ketki Joshi

                Hi Naveen,

                 

                Scan optimization is decided on many factors, can you provide me screenshots for DA(hostinfo,deviceinfo) of all three members? Have you also checked reasoning log in debug mode to understand why system thinks these members are same?

                 

                Thanks,

                Ketki

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                • 5. Re: Regarding scanning skipped IP
                  Naveen Kumar N C

                  Hi Joshi

                   

                  Not verified reasoning log with Debug enabled.

                   

                  But verified now, get host info and device info for all three members.

                   

                  We are getting correct hostname and corresponding discovery access IP's for all three hosts correctly.

                   

                  Under host info getting same serial number/ UUID as all three hosts as these are from same cluster and same template being used to configure it.

                   

                  but inferred host is same for all three

                  • 6. Re: Regarding scanning skipped IP
                    Bob Anderson

                    You seemed to nail the problem on the head - same serial number and perhaps the same mac address for each VM

                     

                    What version of Discovery?

                    How did you create the VMs? 

                     

                    Did you clone them with the virtualizer?  Sometimes the cloning process keeps the same serial number and perhaps mac address.

                    Did you simply copy the original VM to make the others, then change the IP after power up? This also keeps the same serial number and mac address

                     

                    For Discovery, several VMs with different IPs but the same Serial Number and same mac address look like the same machine, thus all get resolved to the first one finished.  The others get scan optimization as either Opt1stScan or OptNotBestIP

                     

                    Perhaps someone with more VM experience can detail how to change the Serial number and/or mac address on the 'cloned/copied' machines.

                    My suggestion is to take a backup of the cluster, rebuild the 2 VMs properly and rebuild the cluster then restore the backup onto the cluster.,

                    3 of 3 people found this helpful
                    • 7. Re: Regarding scanning skipped IP
                      Naveen Kumar N C

                      Hi Bob

                       

                      Thanks for the suggestion.

                       

                      We are running discovery 11.3 version and we have cloned via same template and hence the same UUID.

                       

                      We are trying now with our VM team to modify the UUID to unique values.

                      • 8. Re: Regarding scanning skipped IP
                        David Heydecker

                        I looked at the issue of cloned VMs (both VMware and Microsoft) around a year ago. Unfortunately, the MAC address is not taken into account by the Host Identification Algorithm in these circumstances. If the running VM-based Hosts are individually addressable by IP address, they will have different MAC addresses.

                        In the case of Microsoft VMs, I was able to add the VM Serial Numbers and UUIDs to the bogus identifiers as my customer only had a few source VMs that they were cloning from- please note that this is risky and may not be supported. From memory, I also wrote a pattern to correlate the virtualised Host to its executing VM, based on MAC address rather than Serial Number/UUID; this was pretty reliable as the MAC address was available for the VM.

                        I discussed a similar methodology for VMware with the labs, but obtaining the MAC addresses for the NIC definitions was not straightforward.

                        Unfortunately I am not in a position to share any code, but I hope that this might provide some ideas.

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                        • 9. Re: Regarding scanning skipped IP
                          Girija Sankar Giri

                          Same issue, I had faced in past. These issue happens due to VMWare Cloning phase.

                          As its already well described by @Bob Anderson, Your VMWare team will need to rebuild them and then it will get resolved.

                           

                          Cheers

                          2 of 2 people found this helpful
                          • 10. Re: Regarding scanning skipped IP
                            Andrew Waters

                            This is not true. The MAC address is including in the weighting for determining host identity but it will be insufficient to overcome the same serial number and uuid.

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                            • 11. Re: Regarding scanning skipped IP
                              David Heydecker

                              I stand corrected.

                              Is there an argument for reviewing Host Identification for the cases of VMs? I would suspect that MAC address changes are not frequent and are a good indicator of uniqueness.