error: [Errno 99] Cannot assign requested address for address 2002

I am getting this error: error: [Errno 99] Cannot assign requested address for address 1234
This is my sample test:
Test Rammbock
New Protocol simpleRequest
Chars * testing tls
End Protocol
Start TCP Server 122.143.129.52 1234 name=example.example.com
Start TCP Client 122.143.129.51 protocol=simpleRequest
Connect 122.143.129.52 1234
New Message testing tls
u32 status
Client Sends message
Verify server gets status 0xcafebabe

Start by reproducing the sample using the Start TCP Server, Start TCP Client, and Connect steps, then inspect how those entry points handle the requested addresses. Determine whether the Errno 99 report is caused by invalid or unavailable local addresses; done should include a confirmed cause and an agreed fix or clearer usage guidance.

Written by the indexing model from the issue text.