SCAN lookup request goes to old DNS server

From: Stalin Subbiah <stalinsk_at_gmail.com>
Date: Tue, 11 Mar 2014 14:47:41 -0700
Message-Id: <A32783E0-F1E1-42DF-92CA-912D4ADCEBE3_at_gmail.com>



All,

We recently made some changes to names server which hosts SCAN IPs for a RAC cluster. There is no change in domain name, SCAN Ips or anything, it's just we added another secondary DNS server and added it's IP (10.124.x.x) as the first names server in resolve.conf in all DB nodes, so that transition becomes seamless when we phase out older names server (10.119.x.x).

DB Node --
-bash-3.2$ more /etc/resolv.conf

search domain.com
nameserver 10.124.x.x
nameserver 10.119.x.x

-bash-3.2$ nslookup dbcluster-scan.domain.com
Server: 10.124.x.x
Address: 10.124.x.x#x

Name: dbcluster-scan.domain.com
Address: 10.119.x.x
Name: dbcluster-scan.domain.com
Address: 10.119.x.x
Name: dbcluster-scan.domain.com
Address: 10.119.x.x

As you can see lookup for SCAN in OS seems to pick the right names server for the requests, however network team is seeing scan lookup traffic to 10.119.x.x names server from db node(s). We had 10.119.x.x as the first entry in resolve.conf before and that's the names server we are phasing it out.

Does anyone know if clusterware is caching names server somewhere? I didn't expect this to be case at first but saw this behavior after making this change to the cluster. I also tried dumping OCR but didn't see any info there.

Thanks,
Stalin

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http://www.freelists.org/webpage/oracle-l Received on Tue Mar 11 2014 - 22:47:41 CET

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