Moxa Technologies UC-7420/7410 User Manual
Page 65
UC-7420/7410 User’s Manual
Managing Communication
4-13
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 “P-t-P address” (or point-to-point address) the
address of your server. Here’s what it looks like on one machine:
lo
Link encap Local Loopback
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
ppp0
Link encap Point-to-Point Protocol
inet addr 192.76.32.3 P-t-P 129.67.1.165 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:~$p ping 129.67.1.165
PING 129.67.1.165 (129.67.1.165): 56 data bytes
64 bytes from 129.67.1.165: icmp_seq=0 ttl=225 time=268 ms
64 bytes from 129.67.1.165: icmp_seq=1 ttl=225 time=247 ms
64 bytes from 129.67.1.165: icmp_seq=2 ttl=225 time=266 ms
^C
--- 129.67.1.165 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 247/260/268 ms
waddington:~$
Try typing:
netstat -nr
This should show three routes, something like this:
Kernel routing table
Destination Gateway Genmask Flags
Metric
Ref
Use
iface
129.67.1.165 0.0.0.0
255.255.255.255
UH 0
0 6
ppp0
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
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.