Managing Communication |
How to check the connection
Once you’ve set up a PPP connection, there are some steps you can take to test the connection. First, type:
/sbin/ifconfig
(The folder ifconfig may be located elsewhere, depending on your distribution.) You should be able to see all the network interfaces that are UP. ppp0 should be one of them, and you should recognize the first IP address as your own, and the
lo | Link encap Local Loopback |
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| inet addr 127.0.0.1 Bcast 127.255.255.255 | Mask 255.0.0.0 | |
| UP LOOPBACK RUNNING | MTU 2000 | Metric 1 |
| RX packets 0 errors 0 dropped 0 overrun 0 |
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ppp0 | Link encap |
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| inet addr 192.76.32.3 | Mask 255.255.255.0 | |
| UP POINTOPOINT RUNNING | MTU 1500 | Metric 1 |
RX packets 33 errors 0 dropped 0 overrun 0
TX packets 42 errors 0 dropped 0 overrun 0
Now, type:
ping z.z.z.z
where z.z.z.z is the address of your name server. This should work. Here’s what the response could look like:
waddington:~$p ping 129.67.1.165
PING 129.67.1.165 (129.67.1.165): 56 data bytes
64 bytes from 129.67.1.165: icmp_seq=0 ttl=225 time=268 ms
64 bytes from 129.67.1.165: icmp_seq=1 ttl=225 time=247 ms
64 bytes from 129.67.1.165: icmp_seq=2 ttl=225 time=266 ms ^C
3 packets transmitted, 3 packets received, 0% packet loss
Try typing:
netstat
This should show three routes, something like this: |
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Kernel routing table |
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Destination | Gateway | Genmask | Flags | Metric | Ref | Use |
iface |
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129.67.1.165 | 0.0.0.0 | 255.255.255.255 | UH | 0 | 0 | 6 |
ppp0 |
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127.0.0.0 | 0.0.0.0 | 255.0.0.0 | U | 0 | 0 | 0 lo |
0.0.0.0 | 129.67.1.165 | 0.0.0.0 | UG | 0 | 0 | 6298 |
ppp0 |
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If your output looks similar but doesn’t have the destination 0.0.0.0 line (which refers to the default route used for connections), you may have run pppd without the ‘defaultroute’ option. At this point you can try using Telnet, ftp, or finger, bearing in mind that you’ll have to use numeric IP addresses unless you’ve set up /etc/resolv.conf correctly.