Applications such as Tor Browser, ssh, gpg, wget, curl, git, and apt are configured for stream isolation by default; the full list can be found here. The advantage of this configuration is that these applications will take different paths through the Tor network and will therefore be more anonymous, since it protects against identity correlation through Tor circuit sharing. ^[1]

This arrangement comes with a small usability impact in corner cases:

For some tunnels it may be necessary to disable stream isolation -- this is covered in the Combining Tunnels with Tor chapter.
^[2]

Further information:

Learn more about stream isolation	Disable stream isolation: easy	Disable stream isolation: more options

Footnotes[edit]

↑ If stream isolation is not enforced, different activities conducted in separate applications may pass through the same Tor circuit and exit relay, correlating these activities to the same pseudonym.
↑
It might be required to disable stream isolation for applications that require local connections. For example, this is the case for opening a local ssh listener:
- - If the following command is run: ssh 10.152.152.11, uwt will actually execute torsocks /usr/bin/ssh.anondist-orig 10.152.152.11. In this case, traffic would flow though torsocks via a Tor SocksPort. This will fail for local connections and lead to the following error message:
    - libtorsocks(12021): connect: Connection is to a local address (10.152.152.11), may be a TCP DNS request to a local DNS server so have to reject to be safe. Please report a bug to http://code.google.com/p/torsocks/issues/entry ^[archive] if this is preventing a program from working properly with torsocks
  - This is possibly no longer required thanks to the Whonix ™ default /etc/tor/torsocks.conf ^[archive] configuration file which sets AllowOutboundLocalhost 1.
```
# Set Torsocks to allow outbound connections to the loopback interface.
# If set to 1, connect() will be allowed to be used to the loopback interface
# bypassing Tor. If set to 2, in addition to TCP connect(), UDP operations to
# the loopback interface will also be allowed, bypassing Tor. This option
# should not be used by most users. (Default: 0)
AllowOutboundLocalhost 1
```