To communicate with a dial-in server, you need to gather information about the server. Then edit a few files. Most significantly, you must configure the communications requirements of all dial-in servers that the dial-out system needs to call. You can specify options about a dial-in server, such as an ISP phone number, in the /etc/ppp/options.ttyname file. However, the optimum place to configure peer information is in /etc/ppp/peers/peer-name files.
Use the /etc/ppp/peers/peer-name file to provide information for communicating with a particular peer. /etc/ppp/peers/peer-name allows ordinary users to invoke preselected privileged options that users are not allowed to set.
For example, a nonprivileged user cannot override the noauth option if noauth is specified in the /etc/ppp/peers/peer-name file. Suppose the user wants to set up a link to peerB, which does not provide authentication credentials. As superuser, you can create a /etc/ppp/peers/peerB file that includes the noauth option. noauth indicates that the local system does not authenticate calls from peerB.
The pppd daemon reads /etc/ppp/peers/peer-name when pppd encounters the following option:
You can create a /etc/ppp/peers/peer-name file for each target peer with which the dial-out system needs to communicate. This practice is particularly convenient for permitting ordinary users to invoke special dial-out links without needing root privileges.
Typical options that you specify in /etc/ppp/peers/peer-name include the following:
Supply user-name to the dial-in server, as the login name of the dial-out system, when authenticating with PAP or CHAP.
Use peer-name as the name of the dial-in system. remotename is used in conjunction with PAP or CHAP authentication when scanning the /etc/ppp/pap-secrets or /etc/ppp/chap-secrets files.
connect "chat chat_script..."
Open communication to the dial-in server by using the instructions in the chat script.
Do not authenticate the peer peer-name when initiating communications.
Set the initial IP address that is used in negotiating with the peer to 0.0.0.0. Use noipdefault when setting up a link to most ISPs to help facilitate IPCP negotiation between the peers.
Install a default IPv4 route when IP is established on the link.
See the pppd(8) man page for more options that might apply to a specific target peer.
The /etc/ppp/peers/myisp.tmpl file contains helpful comments about the /etc/ppp/peers/peer-name file. The template concludes with common options that you might use for an /etc/ppp/peers/peer-name file:
connect "/usr/bin/chat -f /etc/ppp/myisp-chat" user myname remotename myisp noauth noipdefault defaultroute updetach noccp
connect "/usr/bin/chat -f /etc/ppp/myisp-chat" calls the peer by using the chat script /etc/ppp/myisp-chat.
user myname is the account name for the local system. myname is the name for this system in the peer's /etc/ppp/pap-secrets file.
remotename myisp recognizes myisp as the name of the peer in the local system's /etc/ppp/pap-secrets file.
noauth does not require calling peers to provide authentication credentials.
noipdefault does not use a default IP address for the local system.
defaultroute uses the default route that is assigned to the local system.
updetach logs errors in the PPP log files, rather than on the standard output.
noccp does not use CCP compression.
To use /etc/ppp/peers/myisp.tmpl at your site, rename /etc/ppp/peers/myisp.tmpl to /etc/ppp/peers/.peer-name. Replace peer-name with the name of the peer to be called. Then modify the file contents as needed by your site.
To find examples of the /etc/ppp/peers/peer-name files, refer to the following:
How to Add PAP Support to the PPP Configuration Files on Dial-Out Systems.
How to Add CHAP Support to the PPP Configuration Files on a Dial-Out System.