SLIP connection won't work

SLIP connection won't work

Post by terh.. » Mon, 28 Aug 1995 04:00:00



I have problems setting up a SLIP connection using dip in dialout mode.
The script I use seems to work fine. ifconfig tells me I am connected to
my service provider. But I can't send any data using ping, neither can
netscape or similar programs set up a connection.

My script file looks like this:

main:
  get $local terhech.berlin.snafu.de

  get $remote berlin.snafu.de

  netmask 255.255.255.255

  port cua0
  speed 38400

  reset

  send ATQ0V1E1X1\r
  wait OK 2
  dial p25431288
  print $errlvl

login:
  sleep 3
  send \r\n\r\n
  wait ogin: 20
  send (her comes my loginname)\n
  wait ord: 20
  send (here comes my password)\n
loggedin:

  get $mtu 1006
  default

done:
  print CONNECTED $locip ---> $rmtip
  mode SLIP
  goto exit

exit:
  exit

Afterwards ifconfig gives me the following messages:

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Bcast:127.255.255.255  Mask:255.0.0.0
          UP BROADCAST LOOPBACK RUNNING  MTU:2000  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0
          TX packets:30 errors:0 dropped:0 overruns:0

sl0       Link encap:Serial Line IP  
          inet addr:194.64.152.95  P-t-P:194.64.64.1  Mask:255.255.255.0
          UP POINTOPOINT RUNNING  MTU:1006  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0
          TX packets:0 errors:0 dropped:0 overruns:0

This looks like a connection has been made, doesn't it?
The only thing I find confusing is that in the dip script I have set Netmask
to 255.255.255.255, but ifconfig tells me it's 255.255.255.0

After that when I use ping to test the connection, I keep getting the
message "Network unreachable".

I am using LINUX version 1.2.9. What is it that I am doing wrong?

---------------------------------------------------
Christoph Terhechte who hates emoticons
---------------------------------------------------

 
 
 

SLIP connection won't work

Post by Terry Dawso » Wed, 30 Aug 1995 04:00:00



> lo        Link encap:Local Loopback  
>           inet addr:127.0.0.1  Bcast:127.255.255.255  Mask:255.0.0.0
>           UP BROADCAST LOOPBACK RUNNING  MTU:2000  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0
>           TX packets:30 errors:0 dropped:0 overruns:0

> sl0       Link encap:Serial Line IP  
>           inet addr:194.64.152.95  P-t-P:194.64.64.1  Mask:255.255.255.0
>           UP POINTOPOINT RUNNING  MTU:1006  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0
>           TX packets:0 errors:0 dropped:0 overruns:0

> This looks like a connection has been made, doesn't it?
> The only thing I find confusing is that in the dip script I have set Netmask
> to 255.255.255.255, but ifconfig tells me it's 255.255.255.0

Not necessarily, it looks like you have a slip device configured,
that doesn't speak anything of whether you have a connection.

The netmask changed because a netmask of 255.255.255.255 on an
interface is always an illegal one. A netmask of 255.255.255.255
suggests a network of exactly one host, yours. This could only
ever make sense for something like the loopback interface.

Quote:> After that when I use ping to test the connection, I keep getting the
> message "Network unreachable".

You'll need to supply the output of 'route -n' before anyone can
help you on a routing problem.

I would expect your 'route -n' to look something like:

$ route -n
Kernel routing table
Destination     Gateway         Genmask         Flags MSS    Window Use Iface
127.0.0.1       *               255.255.255.255 UH    1936   0     6870 lo
194.64.152.95   *               255.255.255.0   UN    1436   0       xx sl0
194.64.64.1     *               255.255.255.255 UH    ???    0       xx sl0
default         194.64.64.1     *               UG    ???    0       xx sl0

regards
Terry

 
 
 

1. PPP connection works well ,while SLIP connection doesn't work,why and how?

Hello.

  Can anyone offer suggestions on how to establish a TCP/IP link using
a
nullmodem between two linux boxes?

  I have consulted the Linux Networking-HOWTO (Using common PC
hardwareNET),the manual of slattach and dip, as well as all the other
documentation that i could find.

  I used two machines running Redhat linux 7.2.

I've tried both SLIP (slattach) and PPP (pppd).When I use PPP(pppd),it
works well ,while I use SLIP(slattach),it do not work.

   For PPP, this is what I am doing :
At  machine 1,run this command:
pppd -detach debug kdebug 4 /dev/ttyS1 local noauth
192.168.1.1:192.168.1.2 &

At  machine 2,run this command:
pppd -detach debug kdebug 4 /dev/ttyS1 local noauth
192.168.1.2:192.168.1.1 &

After run these command ,I can ping between these two machines.

Just because the PPP works well,the null modem line and the serial
port are all OK!

  For slip, this is what I am doing:
At  machine 1,run this command:
% slattach -d -L -p slip /dev/ttyS11 &
%
% ifconfig sl0 192.168.1.1 pointopoint 192.168.1.2 up
%
% route add -host 192.168.1.2 sl0

At  machine 2,run this command:
% slattach -d -L -p slip /dev/ttyS11 &
%
% ifconfig sl0 192.168.1.2 pointopoint 192.168.1.1 up
%
% route add -host 192.168.1.1 sl0

  When I use SLIP,the ifconfig and route command work well,while  ping
doesnot work well!!

  Is this all that I need to do, or is there additional tools I need
to run to
connect.

  Thanks for any help!

2. NAT Scenario

3. Slip connection won't appear in routing table

4. DEC Multia 166 documentation

5. SLIP/DIP interactively works, but can't see connection via ifconfig

6. Help : X11 servers

7. SLIP or PPP won't work!

8. help: external modem on redhat 6.1

9. SLIP: the nameserver trick won't work for me.

10. Dip won't work as SLIP server

11. I got SLIP (dip) working, but my nameservers won't kick in

12. SLIP routing won't work.

13. CD won't work, system won't reboot...please help