You can have multiple write connects against a log stream, but only if there is no import connection established for that log stream anywhere in the sysplex. Once one or more applications connect to a log stream as a write connection, any subsequent attempts to connect as an import connection will fail.
You cannot use the IXGIMPRT service against a log stream that has been connected to as a write connection from anywhere in the sysplex.
An import connection, (AUTH=WRITE IMPORTCONNECT=YES) specifies that you want to use the IXGIMPRT request to import log data from one log stream to another, maintaining the same log block identifier and UTC time stamp. You might do this to create a copy of a log stream. You must specify IMPORTCONNECT=YES at connect time in order to use the IXGIMPRT request against a log stream.
You can have only one import connection for a log stream from anywhere in the sysplex. An import connection cannot coexist with a write connection. Once an application connects to a log stream as an import connect, all subsequent AUTH=WRITE IMPORTCONNECT=YES|NO connect requests will fail.
You cannot use the IXGWRITE service against a log stream that has been connected to as an import connection.
You cannot have both a write and an import connection to a log stream and you cannot issue both write and import requests to the same log stream.