Dial up networking procedure for our house

This web page has information on how to build a network connection to the Internet from any computer in our house.  It discusses how to break the connection when done, and how to test that the connection is in place.
The advantage of a shared network is that it eliminates contention for the phone line.  Several people at several machines may access the network simultaneous.  True, performance suffers, but most users feel that degraded performance is better than getting completely locked out.
In this essay, text written in fixed width type is a computer conversation.  What you type is underlined.  Where you have to substitute something, that is written in italics.



Setup a connection

To start the connection, login to the ppp account.  There is no password.  If you are in the root account, then use the script /etc/ppp/ppp-on to start the network connection.  It generally takes about 10 to 30 seconds to dial the number, answer the phone, establish the carriers, and negotiate the ppp protocol.  So wait about 30 seconds and then test the connection as shown below.  If the connection doesn't get estbalished the first time, then try again.  If the connection just won't setup, then look at the file /var/log/messages for more and possibly helpful information.

Check on the connection

To check on the connection status, use the ifconfig command with no arguments.  If it shows the ppp0 connection, then the internet connection is up.
 [root@angel /root]# ifconfig
lo        Link encap:Local Loopback
          inet addr:  Bcast:  Mask:
          RX packets:23784 errors:0 dropped:0 overruns:0
          TX packets:23784 errors:0 dropped:0 overruns:0

eth0      Link encap:Ethernet  HWaddr 00:60:67:2D:4F:48
          inet addr:  Bcast:  Mask:
          RX packets:655013 errors:0 dropped:10 overruns:0
          TX packets:670040 errors:23 dropped:0 overruns:0
          Interrupt:11 Base address:0x6000

ppp0      Link encap:Point-to-Point Protocol
          inet addr:  P-t-P:  Mask:
          UP POINTOPOINT RUNNING  MTU:1500  Metric:1
          RX packets:4757 errors:0 dropped:0 overruns:0
          TX packets:4501 errors:0 dropped:0 overruns:0

[root@angel /root]#

Stop the connection

 To stop the connection, either in the root or ppp accounts run the /etc/ppp/ppp-off script.  However, it is recomended that you not bother- if the link is inactive for 10 minutes, it will drop automatically.  Not stopping the connection is safer for other potential users.

Background information

Our network is logically a bus style network but physically it is a tree.

       |          |           |          |              |
       PC         PC          PC         PC             PC w/Linux<-->modem-----> the internet

In our network, the bus (the long horizontal line) is actually inside the hub, and the short vertical lines are the wires leading to the computers.
Network resources at our house
Computer IP address Ethernet Address
Jeff's Linux 486  "Angel" 00-60-67-2d-4f-48
Jeff's Windows/95 "Doom" 00:60:8C:66:C5:3D
Daniels' Pentium "portal" 00-a0-24-1d-c4-77
Sarah's Pentium "rex"
Chris's Pentium "Pathfinder" 00:60:67:2D:4F:35