SQL5043N Support for one or more communications protocols specified in the DB2COMM environment variable failed to start successfully. However, core database manager functionality started successfully

Cause:
When installing DB2 as non-root Users ( eg. db2inst1 ), the DB2 COMM port is not listening after installing DB2 Server manually using db2_install
Resolution:
 1. Ensure TCP/IP Communication

1. Before you begin, confirm TCP/IP communication on the IBM DB2 server. Do the following:

• Enter su - <db2InstanceName>where <db2InstanceName> is the IBM DB2 instance owner such as db2inst1.
• Run the following command in the DB2 command window:
  

  db2set -all DB2COMM

  
  
• If a tcpip entry (indicating TCP/IP communication) is not in the list returned by the db2set -all DB2COMM command, run the following command, including tcpip and any other values that were returned in the list that the command provided.
  

  db2set DB2COMM=tcpip

 2. Configure DB2 Parameter SVCENAME

•             db2 get dbm cfg | grep SVCENAMEif above command result no value, then set the SVCENAME parameter using the
  following command
• db2 update dbm cfg using SVCENAME 50000

 3.  Add an entry in /etc/services as follows as root users or if db2inst1 has sudo previleges
DB2_db2inst1    60006/tcp
DB2_db2inst1_1  60007/tcp
DB2_db2inst1_2  60008/tcp
DB2_db2inst1_3  60009/tcp
DB2_db2inst1_4  60010/tcp
DB2_db2inst1_END        60011/tcp
db2c_db2inst1   50000/tcp
then enter the following command to reflect the conf. changes by login as Instance (db2inst1) user

~$db2 set -all

~$db2stop
~$db2start

Now the DB Service will start successfully as follows
SQL1063N  DB2START processing was successful.
SQL1063N  DB2START processing was successful.

To ensure the DB2 Port is listening for db2inst1

>netstat -tanp | grep 50000

tcp        0      0 0.0.0.0:50000               0.0.0.0:*                   LISTEN      2148/db2sysc 0