You're sitting in an airport or in a cafe, and people want your money for Internet access. They do allow ICMP traffic, though (i.e., you can ping machines on the Internet). Enters ICMPTX. (If you can't use ping, but you can issue name queries, use NSTX: IP-over-DNS.)
Ptunnel is an application that allows you to reliably tunnel TCP connections to a remote host using ICMP echo request and reply packets, commonly known as ping requests and replies. At first glance, this might seem like a rather useless thing to do, but it can actually come in handy in some cases. The following example illustrates the main motivation in creating ptunnel: You're on the go, and stumble across an open wireless network. The network gives you an IP address, but won't let you send TCP or UDP packets out to the rest of the Internet, for instance to check your mail. What to do? By chance, you discover that the network will allow you to ping any computer on the rest of the Internet. With ptunnel, you can utilize this feature to check your mail, or do other things that require TCP.
Ptunnel is not a feature-rich tool by any means, but it does what it advertises. So here is what it can do: tunnel TCP using ICMP echo request and reply packets; connections are reliable (lost packets are resent as necessary); handles multiple connections; acceptable bandwidth (150 kb/s downstream and about 50 kb/s upstream are the currently measured maximums for one tunnel, but with tweaking this can be improved further);
and, authentication, to prevent just anyone from using your proxy. To make all of this work you will need one computer accessible on the Internet that is not firewalled (or at least allows incoming ICMP packets); a computer to act as the client (this will usually be your laptop, on the go..); root access, preferably on both computers; a posix-compliant OS, with libpcap (for packet capturing); and/or, Windows with mingw and WinPcap installed.
Ptunnel is an application that allows you to reliably tunnel TCP connections to a remote host using ICMP echo request and reply packets, commonly known as ping requests and replies. At first glance, this might seem like a rather useless thing to do, but it can actually come in handy in some cases. The following example illustrates the main motivation in creating ptunnel: You're on the go, and stumble across an open wireless network. The network gives you an IP address, but won't let you send TCP or UDP packets out to the rest of the Internet, for instance to check your mail. What to do? By chance, you discover that the network will allow you to ping any computer on the rest of the Internet. With ptunnel, you can utilize this feature to check your mail, or do other things that require TCP.
Ptunnel is not a feature-rich tool by any means, but it does what it advertises. So here is what it can do: tunnel TCP using ICMP echo request and reply packets; connections are reliable (lost packets are resent as necessary); handles multiple connections; acceptable bandwidth (150 kb/s downstream and about 50 kb/s upstream are the currently measured maximums for one tunnel, but with tweaking this can be improved further);
and, authentication, to prevent just anyone from using your proxy. To make all of this work you will need one computer accessible on the Internet that is not firewalled (or at least allows incoming ICMP packets); a computer to act as the client (this will usually be your laptop, on the go..); root access, preferably on both computers; a posix-compliant OS, with libpcap (for packet capturing); and/or, Windows with mingw and WinPcap installed.
