2896080 - DB6: SQL1768N Unable to start HADR. Reason code = "6"

HADR Standy failed to start and the following information can be found in the db2diag.log of the standby system:

2020-02-17-12.59.20.895488+330 I199926966E488 LEVEL: Info
PID : 12345 TID : 123456789123456 PROC : db2sysc 0
INSTANCE: db2abc NODE : 000 DB : ABC
APPHDL : 0-1234 APPID: *LOCAL.db2abc.123456789123
AUTHID : DB2ABC HOSTNAME: HOSTNAME
EDUID : 1234 EDUNAME: db2agent (ABC) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery, hdrEduStartup, probe:21151
MESSAGE : HADR Startup has begun.

2020-02-17-12.59.20.958224+330 I199928195E536 LEVEL: Error
PID : 12345 TID : 123456789123456 PROC : db2sysc 0
INSTANCE: db2abc NODE : 000 DB : ABC
APPHDL : 0-1234 APPID: *LOCAL.db2abc.123456789123
AUTHID : DB2ABC HOSTNAME: HOSTNAME
EDUID : 1234 EDUNAME: db2agent (ABC) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery, hdrResolveHostNameAndPort, probe:1540
MESSAGE : ZRC=0x810F0032=-2129723342=SQLO_HOST_UNKNOWN "Host unknown"

2020-02-17-12.59.20.961352+330 I199928732E623 LEVEL: Error
PID : 12345 TID : 123456789123456 PROC : db2sysc 0
INSTANCE: db2abc NODE : 000 DB : ABC
APPHDL : 0-1234 APPID: *LOCAL.db2abc.123456789123
AUTHID : DB2ABC HOSTNAME: HOSTNAME
EDUID : 1234 EDUNAME: db2agent (ABC) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery, hdrGetPortByName, probe:1100
MESSAGE : ZRC=0x070F00B8=118423736=SQLO_NOT_FOUND
"Environment/registry variable was not found."
DATA #1 : <preformatted>
Invalid input for port: servicename

2020-02-17-12.59.20.962530+330 E199931128E618 LEVEL: Error
PID : 12345 TID : 123456789123456 PROC : db2sysc 0
INSTANCE: db2abc NODE : 000 DB : ABC
APPHDL : 0-1234 APPID: *LOCAL.db2abc.123456789123
AUTHID : DB2ABC HOSTNAME: HOSTNAME
EDUID : 1234 EDUNAME: db2agent (ABC) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery, hdrResolveAllHostsAndSetIpProtocol, probe:25010
MESSAGE : ZRC=0x87800143=-2021654205=HDR_ZRC_CONFIG_REMOTE_SVC
"HADR_REMOTE_SVC configuration parameter is an invalid service name"

2020-02-17-12.59.20.963141+330 I199933383E563 LEVEL: Error
PID : 12345 TID : 123456789123456 PROC : db2sysc 0
INSTANCE: db2abc NODE : 000 DB : ABC
APPHDL : 0-1234 APPID: *LOCAL.db2abc.123456789123
AUTHID : DB2ABC HOSTNAME: HOSTNAME
EDUID : 1234 EDUNAME: db2agent (ABC) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery, hdrEduStartup, probe:21180
MESSAGE : SQL1768N Unable to start HADR. Reason code = "6".
DATA #1 : ZRC, PD_TYPE_ZRC, 4 bytes
0x87800143

 SAP on IBM Db2 for Linux, UNIX, and Windows

HADR_REMOTE_SVC, /etc/services, invalid input for port, invalid service name, HADR, standby , KBA , BC-DB-DB6 , DB2 Universal Database for Unix / NT , Problem