dialin server not routing/forwarding????

Hi,
I just setup a dialin server on RedHat 9.
Dial in server is a member of LAN with common gateway 192.168.1.1. I can browse internet from dial-in server and I can ping any other PC in the LAN.

From a windows PC i can dial in and connect to the server but I cannot
browse Internet.
When connected to the dial-in server my windows PC has the following ipsettings and I cannot ping
any other PC in the LAN except dial in server (192.168.1.10) I'm connected to:
c:\>ipconfig /all
PPP adapter test2PPP:

       Connection-specific DNS Suffix  . :
       Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
       Physical Address. . . . . . . . . : 00-53-45-00-00-00
       DHCP Enabled. . . . . . . . . . . : No
       IP Address. . . . . . . . . . . . : 192.168.1.171
       Subnet Mask . . . . . . . . . . . : 255.255.255.255
       Default Gateway . . . . . . . . . : 192.168.1.171
       DNS Servers . . . . . . . . . . . : 192.168.1.2
                                                     192.168.1.3

As you see the IP and the gateway for my windows PC are the same - 192.168.1.171. Is this correct?

My guess is that the linux Dial-in server doesn't route/forward packets from PPP to the rest of the LAN?
How I can prove if it's true or not?
Which config files/log files to be check out?
Which tools I can use to debug it?

Thank you for the help in advance!
Milen
=================
Please see some of config files bellow:
1. /etc/sysctl.conf
contains the line:
--------------------------
net.ipv4.ip_forward = 1
--------------------------
so cat /proc/sys/net/ip4fw/ip_forward
shows "1"

/etc/ppp/options
contains:
-----------------------
-detach
asyncmap 0
netmask 255.255.255.0
proxyarp
lock
crtscts
modem
noauth
ms-dns 192.168.1.1
ms-dns 192.168.1.1
---------------------

/etc/ppp/options.ttyS0
contains:
-----------------------
192.168.1.10:192.168.1.171
-----------------------

No idea. I don't use Windows. It looks goofy, so may as well assume that it's ok. ;-}

Yes, that seems like a reasonable guess. As a further guess, I suspect that your Linux system has a "proxy ARP" tunable somewhere, and that you don't have proxy ARP enabled. Since this connection appears to be configured for proxy ARP, you'll need to turn that on.

You might want to ditch that. It doesn't help on point-to-point links.

That's strange. Your PC is reporting different addresses for the DNS server. I wonder why it's not getting these addresses ...

Try adding "debug" to your pppd configuration and making sure that daemon.debug is redirected to a file in /etc/syslog.conf. Please include debug messages with your posting.

It would be nice to know how the network is configured, in order to know if the 'proxyarp' option makes sense here. Include 'netstat -nr' in your next posting, or at least verify that the remote IP address on the PPP link is inside the subnet defined by one of your broadcast-type interfaces (such as an Ethernet interface).

Another good thing to look at would be the output of 'netstat -s' before and after attempting to contact the network from the PC. Look especially at the drop counters.

James Carlson                                  <[email protected]>

I have added comments to your text.

Qn. are you using mgetty for dialin?

My options file contains the following.

lock
dump

My options.dialin (same as your options.ttyS0)

crtscts
modem
debug
lock
login
require-pap
refuse-chap
proxyarp
asyncmap 20a0000
ms-dns 192.168.1.1
ms-wins 192.168.1.1
192.168.1.1:

My ip-up contains the following

/sbin/route add -net $5 netmask 255.255.255.0 ppp0 /etc/rc.d/rc.pppfirewall

The last one configures the firewall (IPCHAINS) to allow packet
forwarding between ppp0 <-> eth1 (Internet), ppp0 <-> lo, ppp0 <-> eth0, ppp0 <-> eth2

/etc/mgetty+sendfax/dialin.config = empty

/etc/mgetty+sendfax/mgetty.config

port ttyS0
init-chat "" ATZ\r OK
rings 2
answer-chat "" ATA CONNECT \c
issue /etc/issue

/etc/mgetty+sendfax/login.config

/AutoPPP/ - a_ppp /usr/sbin/pppd file /etc/ppp/options.dialin

^^^^^ Yes, I could have put the standard options on the end in the
file, but I have a limit of how many I can use in the login.config file, as "file xxxx" is a valid option, I used that to grab the options from an external file ;o)

/etc/ppp/pap-secrets

user1   *   ""   192.168.1.3
user2   *   ""   192.168.1.4

^^^^ Having "" as password allows the use of the password stored in
PAM/Shadow

I have a web proxy server running, so the windows dialin box will
use that proxy instead of directly to the Internet