Dear Rishi,
I checked msg server port number at SMMS. it is 3300 only.
Now I restarted my portal server and error changed as below.
ERROR partner '127.0.0.1:sapgw00' not reached
before it was
ERROR partner '127.0.0.1:3300' not reached
host entries and service entries are already maintained.
what might be the issue.
Regards,
Venkat