Commands Reference, Volume 4

pppattachd Daemon

Purpose

Attaches an asynchronous device stream to the PPP (Point to Point Protocol) subsystem. Can be invoked as a daemon or a normal process.

Syntax

To Use a Specific tty Port as a Connection (Runs as a Daemon):

pppattachd /dev/ttyPortNumber { client | server | demand } [ multilink ] [ connect "ConnectorProgram" ] [ inactive Seconds ] [ authenticate pap | chap ] [ peer pap | chap ] [ user Name ] [ remote HostName ] [ nodaemon ]

To Use Standard In and Standard Out as the tty Device (Runs as a Process):

pppattachd { client | server | demand } [ multilink ] [ inactive Seconds ] [ authenticate pap | chap ] [ peer pap | chap ] [ user Name ] [ remote HostName ] [ nodaemon ]

The pppattachd daemon provides the mechanism to bind an asynchronous stream to the PPP subsystem. When placing an out going connection on a specific tty port, pppattachd becomes a daemon. When using stdin (standard in) and stdout (standard out) as the tty device for PPP communications pppattachd does not become a daemon. (It would be exec'd from the $HOME/.profile upon login on a tty device.)

You can activate PAP or CHAP authentication with the authenticate and peer options. Use the smit command to create entries in either the /etc/ppp/pap-secrets or /etc/ppp/chap-secrets file. The pppattachd daemon uses the passwords in these files to authenticate the connection. It searches only the /etc/ppp/pap-secrets file for PAP authentication and the /etc/ppp/chap-secrets file for CHAP authentication.

In AIX 4.2 or later, the multilink option is to used to identify the PPP link as having several attachments between the two PPP peers. PPP packets are fragmented at one peer, sent over the multiple attachments, and then reconnected on the remote peer that must also support multilink. The maximum receive reconstruction unit (MMRU) and endpoint descriptor are set through SMIT on the PPP Link Configuration menu. MRRU is the maximum data size before fragmentation. The endpoint discriminator uniquely identifies the local system.

Errors and messages are logged using the syslog facility.

Options

authenticate pap \| chap	Defines the current system as the authenticator of either PAP or CHAP.
client \| server \| demand	Defines the type of subsystem connection to be bound to on the system running the daemon.
connect "ConnectorProgram"	Specifies the program to use to place an outgoing connection. The tty device opened is passed as stdin and stdout to the program. The /usr/sbin/pppdial command is a connector program that can be used.
inactive Seconds	Specifies the number (unsigned integer) of seconds to wait for inactivity on the link before terminating the connection. The default value is 0 (no timeout).
multilink	Identifies the PPP link as having a group of attachments connecting to two PPP peers. This option only applies to AIX 4.2 or later.
nodaemon	Specifies to the attachment process that it is not to become a daemon. You must use this option for attachment processes which are invoked with demand connections.
peer pap \| chap	Defines the current system as the peer of either PAP or CHAP.
remote HostName	Defines the remote host name to be used for PAP authentication. An entry for UserName RemoteHostName Password must exist in /etc/ppp/pap-secrets file for a successful connection. This option only has meaning for PAP authentication on both the authenticator and peer.
user Name	Defines the user entry to use for PAP authentication. An entry for UserName RemoteHostName Password must exist in /etc/ppp/pap-secrets file for a successful connection. This option only has meaning for PAP authentication on the peer.

Exit Status

This command returns the following exit values:

0	Successful completion.
!0	An error occurred.

Security

Access Control: Any User

Auditing Events: N/A

Examples

You want System A to act as a client to server System B. From System A enter:
```
/usr/sbin/pppattachd /dev/tty0 client connect "sysbconnector" 
```
where sysbconnector is the connector program.
On System B, the user which logged in would have invoked from $HOME/.profile:
```
exec /usr/sbin/pppattachd server 2>/dev/null
```
You want server System B to contact client System A. From System B enter:
```
/usr/sbin/pppattachd /dev/tty0 server connect "sysaconnector"
```
where sysaconnector is the connector program.
On System A, the user which logged in would have invoked from $HOME/.profile:
```
exec /usr/sbin/pppattachd client 2>/dev/null
```
You want System A to act as a client to server System B using PAP authentication. System B acts as the authenticator and System A is the peer to be authenticated. From System A enter:
```
/usr/sbin/pppattachd /dev/tty0 client peer pap user username \
connect "sysbconnector"
```
where sysbconnector is the connector program.
On System A, the /etc/ppp/pap-secrets file contains: username * ppppassword. On System B the user which logged in would have invoked from $HOME/.profile:
```
exec /usr/sbin/pppattachd server authenticate pap 2>/dev/null
```
On System B, the /etc/ppp/pap-secrets file contains: username * ppppassword.

Files

/usr/sbin/pppattachd	Contains the pppattachd daemon.
/etc/ppp/attXXX.pid	Contains the process id. XXX is the pid, the content of the file is the network layer id which the attachment was bound to. The user must belong to uucp group for the pid file to be created.

Related Information

The pppcontrold daemon, pppdial command.

The syslog subroutine.

The profile file format.

Asynchronous Point-to-Point Protocol (PPP) Subsystem Overview in AIX 5L Version 5.1 System Management Guide: Communications and Networks.