Could not create pool connection. The DBMS driver exception Was:io exception: Broken pipe

On-site colleague feedback: middleware WebLogic not connected to the database Oracle, sent back to the log can be seen:
caused by:weblogic.common.ResourceException:weblogic.common.ResourceException:Could not create pool connection. The DBMS driver exception Was:io exception: Broken pipe
At Weblogic.jdbc.common.internal.ConnectionEnvFactory.createResource (connectionenvfactory.java:256)
At Weblogic.common.resourcepool.ResourcePoolImpl.makeResources (resourcepoolimpl.java:1180)
At Weblogic.common.resourcepool.ResourcePoolImpl.makeResources (resourcepoolimpl.java:1104)
At Weblogic.common.resourcepool.ResourcePoolImpl.start (resourcepoolimpl.java:244)
At Weblogic.jdbc.common.internal.ConnectionPool.doStart (connectionpool.java:1065)
At Weblogic.jdbc.common.internal.ConnectionPool.start (connectionpool.java:146)
At Weblogic.jdbc.common.internal.ConnectionPoolManager.createAndStartPool (connectionpoolmanager.java:385)
At Weblogic.jdbc.common.internal.ConnectionPoolManager.createAndStartPool (connectionpoolmanager.java:326)
Diagnostic Process:
1. Familiar with the environment, both the application server and the database server are AIX.
2. Detect the connectivity between the application server and the database server, ping the database server on the application server ip,ping a minute, is a pass, and there is no problem of packet loss. Telnet the database server IP: port on the application server, it is pass, connectivity is not a problem.
3. Log in to the database server, view the listening log listener.log, and found that the application server IP is normal.
4. It is still not possible to close the firewall on the database server.
5. Redeploy a domain, build a connection pool, and test is possible. The system is then published on the newly deployed domain and the test system is accessible.
The local diagnostic results are:It is likely that the domain has been damaged.

Could not create pool connection. The DBMS driver exception Was:io exception: Broken pipe