---
name: "ng_sppp"
section: "4"
platform: "linux"
package: "freebsd-manpages"
version: "6.0-5"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/ng_sppp"
---

# ng\_sppp(4)

sppp netgraph node type

## NAME

**ng\_sppp** – sppp netgraph node type

## SYNOPSIS

**#include \<netgraph/ng\_sppp.h\>**

## DESCRIPTION

An **sppp** node is a [netgraph(4)](/netgraph/4.md) interface to the original [sppp(4)](/sppp/4.md) network module for synchronous lines. Currently, [sppp(4)](/sppp/4.md) supports PPP and Cisco HDLC protocols. An **sppp** node could be considered as an alternative kernel mode PPP implementation to *net/mpd* port + [ng\_ppp(4)](/ng_ppp/4.md), and as an alternative to [ng\_cisco(4)](/ng_cisco/4.md) node. While having less features than *net/mpd* + [ng\_ppp(4)](/ng_ppp/4.md), it is significantly easier to use in the majority of simple configurations, and allows the administrator to not install the *net/mpd* port. With **sppp** you do not need any other nodes, not even an [ng\_iface(4)](/ng_iface/4.md) node. When an **sppp** node is created, a new interface appears which is accessible via [ifconfig(8)](/ifconfig/8.md). Network interfaces corresponding to **sppp** nodes are named sppp0, sppp1, etc. When a node is shut down, the corresponding interface is removed, and the interface name becomes available for reuse by future **sppp** nodes. New nodes always take the first unused interface. The node itself is assigned the same name as its interface, unless the name already exists, in which case the node remains unnamed. The **sppp** node allows drivers written to the old [sppp(4)](/sppp/4.md) interface to be rewritten using the newer more powerful [netgraph(4)](/netgraph/4.md) interface, and still behave in a compatible manner without supporting both network modules.

An **sppp** node has a single hook named *downstream*. Usually it is connected directly to a device driver hook.

The **sppp** nodes support the Berkeley Packet Filter, [bpf(4)](/bpf/4.md).

## HOOKS

This node type supports the following hooks:

- *downstream*

  The connection to the synchronous line.

## CONTROL MESSAGES

This node type supports the generic control messages, plus the following:

- NGM\_IFACE\_GET\_IFNAME

  Returns the name of the associated interface as a NUL-terminated ASCII string. Normally this is the same as the name of the node.

## SHUTDOWN

This node shuts down upon receipt of a NGM\_SHUTDOWN control message. The associated interface is removed and becomes available for use by future **sppp** nodes.

Unlike most other node types and like [ng\_iface(4)](/ng_iface/4.md) does, an **sppp** node does *not* go away when all hooks have been disconnected; rather, an explicit NGM\_SHUTDOWN control message is required.

## EXAMPLES

For example, if you have the [cx(4)](/cx/4.md) device, you could run PPP over it with just one command:

```
ngctl mkpeer cx0: sppp rawdata downstream
```

Now you have the sppp0 interface (if this was the first **sppp** node) which can be accessed via [ifconfig(8)](/ifconfig/8.md) as a normal network interface, or via spppcontrol(8) as an [sppp(4)](/sppp/4.md) interface.

## SEE ALSO

[bpf(4)](/bpf/4.md), [cx(4)](/cx/4.md), [netgraph(4)](/netgraph/4.md), [ng\_cisco(4)](/ng_cisco/4.md), [ng\_iface(4)](/ng_iface/4.md), [ng\_ppp(4)](/ng_ppp/4.md), [sppp(4)](/sppp/4.md), [ifconfig(8)](/ifconfig/8.md), [ngctl(8)](/ngctl/8.md), spppcontrol(8)

For complex networking topologies you may want to look at *net/mpd* port.

## HISTORY

The **sppp** node type was implemented for FreeBSD 5.0. It was included to the system since FreeBSD 5.3.

## AUTHORS

Copyright (C) 2003-2004 Roman Kurakin ⟨rik@cronyx.ru⟩.