Establishing PPP Links

PPP links are established automatically by the PPP link manager when it receives a request for an IP connection. This process is usually transparent; however, you may see minor differences in the response, depending on the type of link you are using.

IP Connections over Synchronous Links

Once a synchronous link is created, it is available for as long as both endpoints remain active. To establish an IP connection across a synchronous link, type a UNIX command and the hostname or IP address that corresponds to the remote end of the link. You should see an almost immediate response to your command, subject to the line speed of your link.

For example, to establish a telnet(1) connection to a remote host over a synchronous link, type:

prompt% /usr/bin/telnet hostname
Trying xxx.xxx.xxx.38 ...
Connected to hostname.
Escape character is '^]'.

UNIX(r) System V Release 4.0 (hostname)

IP Connections over Asynchronous Links

To establish an IP connection across an asynchronous link, type a UNIX command and the hostname or IP address that corresponds to the remote end of the link. When you establish an asynchronous link, there is always a short delay before connection. This is the time it takes to complete the PPP negotiation and to establish the asynchronous link. The delay is typically less than one minute.

You can monitor the progress of the connection by looking at the log file /var/opt/SUNWconn/ppp.log.

IP Connections using Dynamic IP Address Allocation

When dynamic IP address allocation is enabled, you need to invoke a connection phase during which the server provides the client with the IP addresses it needs to establish an IP connection over the PPP link.

Use pppconn(1M) to establish a PPP link to the server:

1. Use pppconn to create the PPP link, to recover the IP information from the server, and to initialize the IP interface.

   prompt# /usr/bin/pppconn hostname Connect to hostname Connecting... Connected over ipdptp0 Local IP address : xxx.xxx.xxx.119 Remote IP address: xxx.xxx.xxx.38 IP mtu : 1500

2. Establish an IP connection over the PPP link by typing a command and hostname. For example:

   prompt% /usr/bin/telnet hostname Trying xxx.xxx.xxx.38 ... Connected to hostname. Escape character is '^]'. UNIX(r) System V Release 4.0 (hostname)

   If there is only one IP interface defined at the client side, you can invoke pppconn without any arguments:

   prompt# /usr/bin/pppconn Connect to hostname Connecting... Connected over ipdptp0 Local IP address : xxx.xxx.xxx.119 Remote IP address: xxx.xxx.xxx.01 IP mtu : 1500

   You can also specify a given IP interface by invoking pppconn with the -i option:

   prompt# /usr/bin/pppconn -i ipdptpn Connect to hostname Connecting... Connected over ipdptpn Local IP address : xxx.xxx.xxx.119 Remote IP address: xxx.xxx.xxx.01 IP mtu : 1500

   To initiate a PPP connection to hostname with a telephone number other than the one specified in the configuration file link.conf, type::

   prompt# /usr/bin/pppconn hostname number Connect to hostname Connecting... Connected over ipdptp0 Local IP address : xxx.xxx.xxx.119 Remote IP address: xxx.xxx.xxx.01 IP mtu : 1500

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   Note -

   When a link is established using pppconn, it remains open until it is closed explicitly, or until the inactivity timer expires. If the link fails while it is still in use, you must stop the IP application before using pppconn to re-establish the link. This step is necessary because you cannot guarantee that the server will assign the same IP address for the new link.

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