An ipc$ connection that does not require a username and password is an empty connection. Once you log in as a user or administrator (that is, ipc$ connection with a specific user name and password), it cannot be called an empty connection.

When you log in with an empty connection, you don't have any rights, but when you log in as a user or administrator, you will have corresponding rights.

2)ipc$ and 139445 ports:

Ipc$ connection can realize remote login and access default * * *; The opening of 139 port indicates the application of netbios protocol. We can access files/printers through port 139,445 (win 2000), so generally speaking, ipc$ connection needs port139 or 445 to support it.

3)ipc$ and default * * *

The default * * * access is enabled by default, so as to facilitate the remote management of the administrator (of course, you can turn it off), that is, all logical disks (C $,D $,E $) ... and the system directory winnt or windows(admin$). We can access these default * * * accesses through ipc$ connection (provided that the other party has not turned off these default * * *).