Cognos BI to operate and co-exist with ipstatus conntrack "stateful "firewall" with "default" configuration settings

New Functionality requested with Cognos:
When Oracle maintenance is required to be carried out there will always be a Cognos CS instance available.
We're seeking for Cognos BI to operate in such a manner to ensure that it ipstatus conntrack table on the Oracle Server is not maxed out bring down Oracle server for other hosted applications.
Suggestions are
- abort attempts to connect to Oracle when the Oracle instance is down for maintenance (heartbeat?) and restart when becomes available again
- utilize WebSphere Datasource for JDBC connection as been informed by Project team that this problem does not occur with Dbases utilizing WebSphere Datasources.
- any other means that would limit the number of connections initiated by Cognos while Oracle Server is down.

Background:
Unexpected behaviour: Cognos is not aborting connections requests when Oracle is down for maintenance

Cognos Server

By Design, in a case of no connectivity to the Contentstore (Oracle instance), CM(Content Manager) will try to establish a new JDBC connection to the CS(Contentstore) for every request sent to CM via an Oracle JDBC driver
The purpose of this behaviour is to allow CM to continue functioning for when CS is back up. Configuration of CM JDBC timeouts/retries has had no effect on the issue.

Oracle Server

Cognos CS Oracle Dbase Instance (that's down for maintenance), on receiving requests from the CM results in flooding of iptable conntrack (connection tracking) records, resulting in a full ip_conntrack table with TIMED_OUT entries

date ; wc -l /proc/net/ip_conntrack ; ps -ef | grep dbkv | grep -c
LOCAL=NO
Mon Sep 21 09:43:49 CEST 2015 45743 /proc/net/ip_conntrack

Oracle Server does NOT just Host the Cognos Content Store, it also support other Dbases for other Applications. For this reason, Response from Oracle Administration team is that the following are NOT options in dealing with such a case
- disabling the iptables firewall
- tuning ipstatus conntrack entry time-outs
- dropping INVALID ipstatus cnntrack entries
- filtering out ipstatus conntrack traffic between Cognos and Oracle Server
The ipstatus conntrack can NOT be tuned due to company policy.