Weblogic Error : Delaying formation of a new cluster; unicast networking appears to be inoperable on interface

While booting up my OSB Managed Server using :-

• Open CMD
• cd C:\Oracle\Middleware\Oracle_Home\user_projects\domains\soa12c_domain\bin 
• startManagedWebLogic.cmd osb_server1 http://Deb_Kriti:7001

I was receiving lots of warning -

<27/03/2019 8:59:13 AM IST> <Warning> <com.oracle.coherence> <BEA-000000> <2019-03-27 08:59:13.218/305.579 Oracle Coherence GE 12.2.1.0.0 <W
arning> (thread=Cluster, member=n/a): Delaying formation of a new cluster; unicast networking appears to be inoperable on interface 192.168.
0.13 as this process isn't receiving even its own transmissions; consider forcing IPv4 via -Djava.net.preferIPv4Stack=true>

And then the server was FORCE SHUTTING DOWN.

I turned off Firewall but it did not work.

I followed this blog article Here and tried the solution 2 :-

Solution 2:

To change the type of coherence the cluster is using, you have to add a property inside the CoherenceSystemResource config file (which is located in the $DOMAIN_HOME/config/coherence folder). The correct *-coherence.xml is the one with the same name as the coherence systemResource as seen in Solution 1 (by default: defaultCoherenceCluster-coherence.xml).

Just add the following highlighted line in the coherence-cluster-params element-tag:

  <coherence-cluster-params>

    <cluster-listen-port>7574</cluster-listen-port>

    <clustering-mode>multicast</clustering-mode>

  </coherence-cluster-params>




This also should lead to the server starting again.

Then I executed 

• startManagedWebLogic.cmd osb_server1 http://Deb_Kriti:7001

It Worked!!! The Server came to RUNNING Mode

However , when I tried starting my second Managed Server it did not work.

Then I attempted Solution 1 

Solution 1:

To remove the coherence cluster awareness of the default server, you just have to remove the coherence-cluster-system-resource tag from the domains config.xml file (which resides in your $DOMAIN_HOME/config folder).

<server>  
  <name>DefaultServer</name>
     …
  <coherence-cluster-system-resource>defaultCoherenceCluster</coherence-cluster-system-resource>
</server>
Just remove the highlighted entry and the server should start (without any awareness of coherence). 

and restarted all 3 servers ( Admin and Managed Servers) .

All came to RUNNING mode.