Slirp
| Developer(s) | Danny Gasparovski, Kelly Price (maintainer) |
|---|---|
| Initial release | March 30, 1995 |
| Stable release | 1.0.17 / January 8, 2006 |
| Operating system | Unix-like |
| Platform | shell account |
| Type | Dial-up access |
| License | BSD-like license |
| Website | slirp.sf.net |
Slirp (sometimes capitalized SLiRP) is a software program that emulates a PPP, SLIP, or CSLIP connection to the Internet via a shell account. It is largely obsolete for its original purpose, as dedicated dial-up PPP connections and broadband Internet access have in turn become widely available and inexpensive. It has also been used for connecting mobile devices, such as PDAs, via their serial ports.
Usage
Shell accounts normally only allow the use of command line or text-based software, but by logging into a shell account and running Slirp on the remote server, a user can transform their shell account into a SLIP/PPP connection, allowing them to run any TCP/IP-based application—including standard GUI software such as the formerly popular Netscape Navigator—on their computer. This was especially useful in the 1990s because simple shell accounts were less expensive and/or more widely available than full SLIP/PPP accounts.[1]
In the mid-1990s, numerous universities provided dial-up shell accounts (to their faculty, staff, and students). These command line-only connections became more versatile with SLIP/PPP, enabling the use of arbitrary TCP/IP-based applications. Many guides to using university dial-up connections with Slirp were published online (e.g. [1], [2], [3], [4]). Use of TCP/IP emulations software like Slirp, and its commercial competitor TIA was banned by some shell account providers, who believed its users violated their terms of service or consumed too much bandwidth.[2][3]
Slirp is also useful for connecting PDAs and other mobile devices to the Internet: by connecting such a device to a computer running Slirp, via a serial cable or USB, the mobile device can connect to the Internet.[4]
Limitations
Unlike a true SLIP/PPP connection, provided by a dedicated server, a Slirp connection does not strictly obey the principle of end-to-end connectivity envisioned by the Internet Protocol suite. The remote end of the connection, running on the shell account, cannot allocate a new IP address and route traffic to it.[5] Thus the local computer cannot accept arbitrary incoming connections, although Slirp can use port forwarding to accept incoming traffic for specific ports.
This limitation is similar to that of network address translation. It does provide enhanced security as a side effect, effectively acting as a firewall between the local computer and the Internet.[5]
Current status
Slirp is free software licensed under a BSD-like license by its original author. After the original author stopped maintaining it, Kelly Price took over as maintainer.[6] However, there have been no further releases since 2006. Debian maintainers have taken over some maintenance tasks, such as modifying Slirp to work correctly on 64-bit computers.[7]
See also
- PPP daemon
- The Internet Adapter, a commercial product that competed with Slirp
References
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- ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
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External links
- Slirp Maintenance Project, official site for recent versions of Slirp
- Latest version of Slirp (1.0.17) from Debian
