5 Replies Latest reply: Apr 16, 2012 1:31 AM by User374733 RSS

    SCAN IP setting

    User374733
      Platform: HPUX IA 64-11.31
      DB: 11.2.0.3
      Nodes: 2
      DNS: Windows based

      We have 3 IPs for single "virtual_hostname.domain_name" as per the clusterware documentation. We have given these 3 IPs against a single host to our system administrator to add them on DNS server as follows:


      IP1 hostname
      IP2 hostname
      IP3 hostname


      But whenever we ping with hostname only IP1 returns, however as per understanding DNS must resolve it in "Round Robin" and Round Robin is enabled in DNS. We have not put the scan IPs in the RAC Node /etc/hosts they only reside in DNS.

      Please suggest how to proceede.



      Regards,
      Umair
        • 1. Re: SCAN IP setting
          912595
          908745 wrote:
          Platform: HPUX IA 64-11.31
          DB: 11.2.0.3
          Nodes: 2
          DNS: Windows based

          We have 3 IPs for single "virtual_hostname.domain_name" as per the clusterware documentation. We have given these 3 IPs against a single host to our system administrator to add them on DNS server as follows:


          IP1 hostname
          IP2 hostname
          IP3 hostname


          But whenever we ping with hostname only IP1 returns, however as per understanding DNS must resolve it in "Round Robin" and Round Robin is enabled in DNS. We have not put the scan IPs in the RAC Node /etc/hosts they only reside in DNS.

          Please suggest how to proceede.



          Regards,
          Umair
          There seems to something wrong in DNS setting itself. So please go through following docs.

          DNS and DHCP Setup Example for Grid Infrastructure GNS [ID 946452.1]
          Linux: How to Configure the DNS Server for 11gR2 SCAN [ID 1107295.1]
          • 2. Re: SCAN IP setting
            User374733
            A new thing we just noted. See the trend of the output coming from nslookup:


            C:\Users\umair.nazir>nslookup ts1scan
            Server: bgdc.bukhatir.ae
            Address: 172.16.102.11

            Name: ts1scan.Bukhatir.ae
            Addresses: 172.16.101.7
            172.16.101.8
            172.16.101.9

            C:\Users\umair.nazir>nslookup ts1scan
            Server: bgdc.bukhatir.ae
            Address: 172.16.102.11

            Name: ts1scan.Bukhatir.ae
            Addresses: 172.16.101.8
            172.16.101.9
            172.16.101.7

            C:\Users\umair.nazir>nslookup ts1scan
            Server: bgdc.bukhatir.ae
            Address: 172.16.102.11

            Name: ts1scan.Bukhatir.ae
            Addresses: 172.16.101.9
            172.16.101.7
            172.16.101.8

            C:\Users\umair.nazir>nslookup ts1scan
            Server: bgdc.bukhatir.ae
            Address: 172.16.102.11

            Name: ts1scan.Bukhatir.ae
            Addresses: 172.16.101.7
            172.16.101.8
            172.16.101.9

            C:\Users\umair.nazir>

            Where "172.16.102.11" is the DNS server IP and the rest 3 IPs are for "SCAN" registered in DNS server. What we can see above is the "alternate" sequence return against "Addresses:" of "ts1scan". Does not it called round robin reslt? Please give your remarks on it.
            • 3. Re: SCAN IP setting
              User374733
              There was no issue in scan ip setting rather there was a misunderstanding. I was using "ping" command to check the scan-name resolution and found that same 1 of the 3 scan IPs is resulted. Then from a document i got an idea of using nlslookup and it clearly showed that all the 3 IPs are being resolved in a round robin fashion.
              • 4. Re: SCAN IP setting
                onedbguru
                You may still have a problem. If you "ping" a scan-name.domain.tld and you consistently hit the same IP address, check your /etc/hosts file as ping should round-robin. I will typically put the first IP address in the /etc/hosts file just to get it installed if all of the other parts are ready to go. Once I have it installed and the DNS is configured correctly, I will go back and modify the SCAN to reflect the correct settings and you must comment out the scan--name entry in /etc/hosts file on ALL nodes.

                What is the output from:
                srvctl status scan
                srvctl status scan_listener
                ???


                You should see something like this (not exact output) if the scans were entered in /etc/hosts:

                nslookup some-scan-name ##nslookup looks at DNS excusively - ping resolves from /etc/hosts first.

                xxx.xxx.xxx.xx1 some-scan-name
                xxx.xxx.xxx.xx2 some-scan-name
                xxx.xxx.xxx.xx3 some-scan-name

                srvctl status scan
                SCAN1 on hostxyz

                edit /etc/hosts and COMMENT OUT all of the scan addresses

                srvctl stop scan_listener
                srvctl sop scan
                srvctl modify scan -n some-scan-name
                srvctl start scan

                srvctl status scan
                SCAN1 enabled on hostxyy
                SCAN2 enabled on hostxyy
                SCAN1 enabled on hostxyz

                srvctl start scan_listener

                srvctl status scan
                SCAN1_LISTENER1 running on hostxyy
                SCAN2_LISTENER2 running on hostxyy
                SCAN3_LISTENER3 running on hostxyz
                • 5. Re: SCAN IP setting
                  User374733
                  ./srvctl status scan
                  SCAN VIP scan1 is enabled
                  SCAN VIP scan1 is running on node ts1db2
                  SCAN VIP scan2 is enabled
                  SCAN VIP scan2 is running on node ts1db1
                  SCAN VIP scan3 is enabled
                  SCAN VIP scan3 is running on node ts1db1
                  root @ ts1db1/gridhome/oragrid/11.2.0/grid/bin >cat /etc/hosts
                  ## Configured using SAM by root on Mon May 30 14:44:58 2011
                  ## Configured using SAM by root on Mon May 30 14:44:19 2011
                  # @(#)B.11.31_LRhosts $Revision: 1.9.214.1 $ $Date: 96/10/08 13:20:01 $
                  #
                  # The form for each entry is:
                  # <internet address> <official hostname> <aliases>
                  #
                  # For example:
                  # 192.1.2.34 hpfcrm loghost
                  #
                  # See the hosts(4) manual page for more information.
                  # Note: The entries cannot be preceded by a space.
                  # The format described in this file is the correct format.
                  # The original Berkeley manual page contains an error in
                  # the format description.
                  #

                  127.0.0.1 localhost.localdomain localhost

                  #Public IP
                  172.16.101.23 ts1db1.bukhatir.ae ts1db1
                  172.16.101.24 ts1db2.bukhatir.ae ts1db2

                  #Vip
                  172.16.101.44 ts1_vip1.bukhatir.ae ts1_vip1
                  172.16.101.45 ts1_vip2.bukhatir.ae ts1_vip2

                  #inerconnect
                  10.0.0.1 ts1_prv1.bukhatir.ae ts1_prv1
                  10.0.0.2 ts1_prv2.bukhatir.ae ts1_prv2

                  root @ ts1db1/gridhome/oragrid/11.2.0/grid/bin >