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Installing SAP Applications on Virtual Host

abarat
Explorer
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We're getting ready to install several SAP applications (ERP, Portal, SolMan, etc.) on Windows 2012 R2/SQL Server 2012 SP1/VMWare environment.  We are going through the prequisite checks.  We would like to install the systems on virtual hosts as mentioned in SAP Notes 962955, 1282975, and 1564275.  We are using DNS for hostname resolution for all of our systems.

We have followed the steps in the notes including creating the DNS A-record and the PTR record pointing to the reverse lookup zone file for the virtual hostname mentioned in SAP Note 129997.  However, it seems after a short period of time that the virtual hostname in PTR record is overwritten with the physical hostname.  Thus, the niping test is failing as is is coming back with the physical hostname. Nslookup looks OK, though.  Here is the niping and nslookup commands:

C:\>niping -v -H <virtual_hostname>

Hostname/Nodeaddr verification:

===============================

Hostname of local computer: <local_pc_hostname>       (NiMyHostName)

Lookup of hostname: <local_pc_hostname>                       (NiHostToAddr)

    --> IP-Addr.: <local_pc_ip_address>

Lookup of IP-Addr.: <local_pc_ip_address>               (NiAddrToHost)

    --> Hostname: <local_pc_hostname>.corporation.com

Lookup of hostname: <virtual_hostname>                             (NiHostToAddr)

    --> IP-Addr.: <virtual_server_IP_Address>

Lookup of IP-Addr.: <virtual_server_IP_Address>    (NiAddrToHost)

    --> Hostname: <physical_hostname>.corporation.com

We expect to see <virtual_hostname>.corporation.com in the last line instead of <physical_hostname>.corporation.com per the SAP notes I mentioned.

Here is nslookup:

C:\>nslookup <virtual_hostname>

Server:  <dns_server_hostname>.corporation.com

Address:  <dns_server_ip_address>

Name:    <virtual_hostname>.corporation.com

Address:  <virtual_server_ip_address>

Has anyone ran into this issue?  Please advise if there are some checks we can run to make sure things look OK.

Thank you!


Avi

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Answers (1)

Answers (1)

former_member188883
Active Contributor
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Hi Avi,

It looks to be problem with your DNS configuration.

Can you check whether your configuration looks like an example stated below

Standard DNS: www.domain.com -> 23.23.212.126

Reverse DNS: 23.23.212.126 -> ec2-23-23-212-126.domain.com

Hope this helps.

Regards,

Deepak Kori

abarat
Explorer
0 Kudos

Hi Deepak,

In a regular situation this would seem to be the correct solution.

However, there seems to be an issue because we have two hostnames and two IP addresses (one for the "physical hostname" and one for the "virtual hostname") per SAP Note 1564275. We have one entry for each hostname in Standard DNS and one entry for each IP address in Reverse DNS as follows::

1. Standard DNS: <hostname_1>.domain.com-> 23.23.212.126

2. Standard DNS:<hostname_2>.domain.com-> 23.23.212.127

3. Reverse DNS: 23.23.212.126 -> <hostname_1>.domain.com

4. Reverse DNS: 23.23.212.127 -> <hostname_2>.domain.com

But what seems to be happening is the Reverse DNS entry for <hostname_2> is getting overwritten by <hostname_1> as follows:

4. Reverse DNS: 23.23.212.127 -> <hostname_1>.domain.com

We believe this is occurring because of the Advanced TCP/IP setting in Windows on the DNS tab, "Register this connection's addresses in DNS". We do not want to uncheck this because of the cleanup that would have to occur in DNS over time.  So, then when we run a niping to the virtual hostname, the lookup of the IP address is resolving to the physical hostname.

Has anyone who has tried to set up multiple hostnames and IP addresses for the purpose of separating their server from their physical network identity (per SAP Note 962955) had this issue?

Thanks.

Avi

Former Member
0 Kudos

Hi Avinash,

Can you try the recommendation in this OSS note (which you referenced already):

1282975 - Use of virtual TCP/IP host names in Windows ...

5. Maintain the ip-address in the Hosts file of the system where this Virtual Hostname is created. Maintain also in the DNS Server so that you can connect to this virtual system from other clients using SAP GUI. Depending on your DNS configuration and SAP transport landscape it's maybe necessary to add all SAP servers with virtual hostnames to the local Hosts file of each server. You can check connections to virtual systems in transaction SM59. Example: You want to transport from QA1 to PR1. The virtual hostnames of the systems are "virtserv1" and "virtserv2". Add both names with their virtual IP address to the Hosts file on each physical server.