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Moxa Technologies UC-7420/7410 User Manual

Page 64

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UC-7420/7410 User’s Manual

Managing Communication

4-12

The pppd options are described below:

connect ‘chat etc...’

This option gives the command to contact the PPP server. The ‘chat’ program is used to dial a
remote computer. The entire command is enclosed in single quotes because pppd expects a
one-word argument for the ‘connect’ option. The options for ‘chat’ are given below:

-v

verbose mode; log what we do to syslog

“ “

Double quotes—don’t wait for a prompt, but instead do ... (note that you must include a
space after the second quotation mark)

ATDT5551212

Dial the modem, and then ...

CONNECT

Wait for an answer.

“ “

Send a return (null text followed by the usual return)

ogin: username word: password

Log in with username and password.

Refer to the chat man page, chat.8, for more information about the chat utility.

/dev/

Specify the callout serial port.

115200

The baud rate.

debug

Log status in syslog.

crtscts

Use hardware flow control between computer and modem (at 115200 this is a must).

modem

Indicates that this is a modem device; pppd will hang up the phone before and after making the
call.

defaultroute

Once the PPP link is established, make it the default route; if you have a PPP link to the Internet,
this is probably what you want.

192.1.1.17

This is a degenerate case of a general option of the form x.x.x.x:y.y.y.y. Here x.x.x.x is the local IP
address and y.y.y.y is the IP address of the remote end of the PPP connection. If this option is not
specified, or if just one side is specified, then x.x.x.x defaults to the IP address associated with the
local machine’s hostname (located in /etc/hosts), and y.y.y.y is determined by the remote machine.

Example 2: Connecting to a PPP server over a hard-wired link

If a username and password are not required, use the following command (note that noipdefault is
optional):

#pppd connect ‘chat –v“ “ “ “ ’ noipdefault /dev/ttyM0 19200 crtscts

If a username and password is required, use the following command (note that noipdefault is
optional, and root is both the username and password):

#pppd connect ‘chat –v“ “ “ “ ’ user root password root noipdefault
/dev/ttyM0 19200 crtscts