[ale] ppp from Windows95 to Linux
Alfred Grahame Leach
aleach at cc.gatech.edu
Tue Aug 13 16:15:03 EDT 1996
Well, I've spent most of the day tracking this problem down. What it
seems to be is that the Linux box isn't forwarding packets for the
machine on the ppp connection to the ppp interface. To clarify the
scenario, here's a picture:
Windows 95 box Linux server
+------------------+ +--------------------------+
| | | |
| | | |
| | | |
| | | |
| | | eth0 +-------> LAN
| | | |
| | | |
| | | |
| | | ppp0 |
+--------+---------+ +----------+---------------+
| |
| |
| |
+----------+ +--------+
| modem | | modem |
+----------+ +--------+
| |
+-----------------------------------+
The problem is that when I contact (from W95) a machine on the ethernet
network the Linux server is connected to, the Linux box gets replies from
this third machine but doesn't forward them back to the Windows machine
on the ppp line so the Windows machine times out. I am using tcpdump to
watch both eth0 and ppp0 on the Linux server, so I'm sure that this is
what's happening, I'm just not sure why - in fact I have no clue why.
I've added a route (in the Linux server) for all traffic headed for the IP
address assigned to the Windows machine to be forwarded to the ppp
interface, but it seems to be ignored. I've also done the arp -s
suggested by C. Fowler (thanks Christopher). Note - the Linux server
itself can successfully ping the Windows machine over the ppp line and
vice versa...
Any ideas? I'd really appreciate any clues anybody can offer. Sorry to
be taking up so much bandwidth on this list!
- al
+-----------------------+----------------------------+-------------------+
| Al Leach | Georgia Tech | Sailing is: |
| Graduate Student | College of Computing | hours and hours |
| MS, CS/Networking | Atlanta, GA 30332 | of boredom, |
+-----------------------+----------------------------| punctuated by |
| email: aleach at cc.gatech.edu | moments of sheer |
| WWW: http://www.cc.gatech.edu/people/home/aleach | stark terror... |
+----------------------------------------------------+-------------------+
| < Georgia Tech - Olympic Village of the 1996 Summer Olympics > |
+----------------------------------------------------+-------------------+
On Tue, 13 Aug 1996, Alfred Leach wrote:
>
>
> Thanks to all who have responded so far. I attempted to send an update
> yesterday, but failed so here's what I've learned so far...
>
> First some background:
> ----------------------
> I can do ppp to the Linux server in question from another Linux box.
> This is done using a special login (user name ppp) who's default shell is
> a script which launches pppd on the server.
>
> My goal is to do ppp from Windows 95 to this same Linux server. I can do
> this, but not with the ppp login mentioned above. Instead I must setup
> W95 to give me a terminal window instead of attempting to login
> automatically. I login as a different user (one who has a bash shell)
> and execute the script which serves as the shell for the ppp user then
> hit continue and I'm in like flynn... (I'm really interested in why
> logging-on with the terminal window works, but the automatic login fails,
> but I can accept this login process - it's not pretty but it works.)
>
>
> Remaining problem:
> ------------------
> Although I can connect and establish a ppp session with the Linux server,
> I can only see myself and the Linux server when I go out and ping
> around. W95 is setup to use the default gateway of the host (i.e. the
> Linux server), but it doesn't seem to be doing this. I've tried
> establishing gateways statically on the Windows 95 machine (client) to
> point to both the Linux server or the Linux server's default gateway,
> but I still can't see beyond the Linux server. The script I'm running on
> the Linux side upon login is:
>
> #!/bin/bash
> # This is the script to run as specified in the Network Administrator's Guide
>
> # ppplogin - script to fire up pppd on login
> mesg n
> stty -echo
> exec /usr/sbin/pppd <Linux server IP addr>:<Windows 95 client IP addr>
> -detach silent modem crtscts netmask 255.255.255.0 debug
>
>
> The output from this script upon login of the Windows 95 machine is:
>
> Aug 13 07:50:15 aleach-pc login: DIALUP ttyS0, dialup
> Aug 13 07:50:20 aleach-pc syslog: Warning - secret file /etc/ppp/pap-secrets has world and/or group access
> Aug 13 07:50:20 aleach-pc pppd[3915]: pppd 2.1.2 started by dialup, uid 503
> Aug 13 07:50:20 aleach-pc pppd[3915]: Using interface ppp0
> Aug 13 07:50:20 aleach-pc pppd[3915]: Connect: ppp0 <--> /dev/ttyS0
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_rconfreq(LCP): Rcvd id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(LCP): Sent code 1, id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: LCP: sending Configure-Request, id 1
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd ASYNCMAP
> Aug 13 07:50:23 aleach-pc pppd[3915]: (a0000)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd MAGICNUMBER
> Aug 13 07:50:23 aleach-pc pppd[3915]: (19e0ac)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd PCOMPRESSION
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd ACCOMPRESSION
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd unknown option 13
> Aug 13 07:50:23 aleach-pc pppd[3915]: (REJ)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: returning CONFREJ.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(LCP): Sent code 4, id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_rconfack(LCP): Rcvd id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_rconfreq(LCP): Rcvd id 2.
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd ASYNCMAP
> Aug 13 07:50:23 aleach-pc pppd[3915]: (a0000)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd MAGICNUMBER
> Aug 13 07:50:23 aleach-pc pppd[3915]: (19e0ac)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd PCOMPRESSION
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: rcvd ACCOMPRESSION
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: lcp_reqci: returning CONFACK.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(LCP): Sent code 2, id 2.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(IPCP): Sent code 1, id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: IPCP: sending Configure-Request, id 1
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_rconfreq(IPCP): Rcvd id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: received COMPRESSTYPE
> Aug 13 07:50:23 aleach-pc pppd[3915]: (45)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: received ADDR
> Aug 13 07:50:23 aleach-pc pppd[3915]: (0.0.0.0)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (NAK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (REJ)
> Aug 13 07:50:23 aleach-pc last message repeated 3 times
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: returning Configure-REJ
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(IPCP): Sent code 4, id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: input: Unknown protocol (80fd) received!
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(LCP): Sent code 8, id 2.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_rconfack(IPCP): Rcvd id 1.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_rconfreq(IPCP): Rcvd id 2.
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: received COMPRESSTYPE
> Aug 13 07:50:23 aleach-pc pppd[3915]: (45)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: received ADDR
> Aug 13 07:50:23 aleach-pc pppd[3915]: (0.0.0.0)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (NAK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: returning Configure-NAK
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(IPCP): Sent code 3, id 2.
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_rconfreq(IPCP): Rcvd id 3.
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: received COMPRESSTYPE
> Aug 13 07:50:23 aleach-pc pppd[3915]: (45)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: received ADDR
> Aug 13 07:50:23 aleach-pc pppd[3915]: (171.68.113.48)
> Aug 13 07:50:23 aleach-pc pppd[3915]: (ACK)
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: returning Configure-ACK
> Aug 13 07:50:23 aleach-pc pppd[3915]: fsm_sdata(IPCP): Sent code 2, id 3.
> Aug 13 07:50:23 aleach-pc pppd[3915]: ipcp: up
> Aug 13 07:50:23 aleach-pc pppd[3915]: local IP address 171.68.113.84
> Aug 13 07:50:23 aleach-pc pppd[3915]: remote IP address 171.68.113.48
>
>
> It looks like some of the connection setup negotiations are not
> successful, but this may be no big deal - the Windows box is setup to
> support IPX and NetBEUI, so it may be a handshake for one of these
> causing the 'Unknown protocol' message. What I need is for the Windows
> 95 machine to be able to see its DNS server. I've tried adding static
> routes to the network where the Windows 95 machine expects to find its
> DNS servers, and although the Linux box can get to them fine the Windows
> 95 machine can't. I realize this means I can't resolve host names, so
> all my pings from the Windows 95 machine have specified IP addresses
> instead - and I still can't get anywhere.
>
>
> Thanks for any help anyone can offer.
>
>
> - Al Leach
>
> (aleach at cc.gatech.edu)
> (aleach at cisco.com)
>
>
> | | Al Leach, Summer Intern
> ||| ||| desk: (919)472-2281
> .|||||..|||||. pager: 800-796-7363 pin# 100-0396
> cisco Systems, Inc. email: aleach at cisco.com
>
>
>
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