[ale] ppp from Windows95 to Linux -- FIXED (almost)
Alfred Grahame Leach
aleach at cc.gatech.edu
Tue Aug 13 19:08:58 EDT 1996
Well, it finally works. It turns out that all that was needed was for me
to add the proxy arp entry using arp -s and add a route entry to forward
packets received to the ppp interface. I did this unsuccessfully many
times this afternoon, but it works now. In my hacking I noticed that the
MAC address corresponding to my ppp machine's IP address was unfamiliar
this afternoon - I think what's happening is that somebody is using my IP
address, and now (after hours) they're gone and this works. I'll spend
tomorrow hunting them down and flogging them :-).
Thanks again for all the help. Hopefully, this will be the last
message about this topic...
- 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 Grahame Leach wrote:
>
> 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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