Log shipping provides standby server capabilities, which reduces downtime in the event of a system failure. Log shipping allows you to automatically send transaction logs from the source system to the destination system. At the destination system the transaction logs are restored to the BizTalk Server databases, keeping them closely synchronized with the source databases.
Couple of times I found this error “Server is not found or not accessible” while configuring the DR site by executing the stored procedure bts_ConfigureBizTalkLogShippingLog
exec bts_ConfigureBizTalkLogShipping @nvcDescription = ‘<MyLogShippingSolution>’,
@nvcMgmtDatabaseName = ‘<BizTalkServerManagementDatabaseName>’,
@nvcMgmtServerName = ‘<BizTalkServerManagementDatabaseServer>’,
@SourceServerName = null, — null indicates that this destination server restores all databases
@fLinkServers = 1 — 1 automatically links the server to the management database
1. DTC Connectivity between LIVE and DR SQL Instance.
2. There might be some firewall issue where only a particular port has been open to access the LIVE database server. In that case create an alias with same name as LIVE SQL database and then run the stored procedure.
Also refer the MSDN forum link