parentProxy specifies the hostname and port number
of an HTTP parent proxy; it should have the form ‘host:port’.
If the parent proxy requires authorisation, the username and password
should be specified in the variable
the form ‘username:password’. Only Basic authentication
is supported, which is vulnerable to replay attacks.
The main application of the parent proxy support is to cross
firewalls. Given a machine, say
trurl, with unrestricted
access to the web, the following evades a firewall by using an
$ ssh -f -C -L 8124:localhost:8123 trurl polipo $ polipo parentProxy=localhost:8124