--proxy host[:port] (Specify proxy address)
Requests proxying through host:port, using the protocol
specified by --proxy-type.
If no port is specified, the proxy protocol's well-known port
is used (1080 for SOCKS and 3128 for HTTP). When specifying
an IPv6 HTTP proxy server using the IP address rather than
the hostname, the square-bracket notation (for example
[2001:db8::1]:8080) MUST be used to separate the port from
the IPv6 address. If the proxy requires authentication, use
--proxy-auth.
--proxy-type proto (Specify proxy protocol)
In connect mode, this option requests the protocol proto to
connect through the proxy host specified by --proxy. In
listen mode, this option has Ncat act as a proxy server using
the specified protocol.
The currently available protocols in connect mode are http
(CONNECT), socks4 (SOCKSv4), and socks5 (SOCKSv5). The only
server currently supported is http. If this option is not
used, the default protocol is http.
--proxy-auth user[:pass] (Specify proxy credentials)
In connect mode, gives the credentials that will be used to
connect to the proxy server. In listen mode, gives the
credentials that will be required of connecting clients. For
use with --proxy-type http or --proxy-type socks5, the form
should be username:password. For --proxy-type socks4, it
should be a username only.
These credentials can be alternatively passed onto Ncat by
setting environment variable NCAT_PROXY_AUTH, which reduces
the risk of the credentials being captured in process logs.
(Option --proxy-authtakes precedence.)
--proxy-dns type (Specify where to resolve proxy destination)
In connect mode, it provides control over whether proxy
destination hostnames are resolved by the remote proxy server
or locally, by Ncat itself. Possible values for type are:
local - Hostnames are resolved locally on the Ncat host. Ncat
exits with error if the hostname cannot be resolved.
remote - Hostnames are passed directly onto the remote proxy
server. This is the default behavior.
both - Hostname resolution is first attempted on the Ncat
host. Unresolvable hostnames are passed onto the remote proxy
server.
none - Hostname resolution is completely disabled. Only a
literal IPv4 or IPv6 address can be used as the proxy
destination.
Local hostname resolution generally respects IP version
specified with options -4 or -6, except for SOCKS4, which is
incompatible with IPv6.
