I'm trying to use my Gentoo Linux home workstation for connecting to a Windows RAS callback server through analogic telephone line (PSTN).
I'm using pppd and successfully configured pppd's options and chat files, both for the outgoing call and for receiving the incoming callback. All seems going well (negotiation of authentication method, encryption, compression), and at the end I am greeted with the following lines:
local IP address 10.74.49.117
remote IP address 10.74.49.22
The pppd daemon is running and I can even receive the DNS information from the remote host. But there's a problem. Simply I cannot ping any host on the remote network (which is 10.0.0.0/8). For example, I am not able to ping the server 10.74.49.22 !
Normally, I'm connecting to the internet through my homenetwork LAN, which subnet is 192.168.0.0/24. So I have an interface card eth0 (192.168.0.3) and a router as the default gateway (192.168.0.100):
localhost ~ # route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 192.168.0.100 0.0.0.0 UG 0 0 0 eth0
I have tried to exclude all possible problems, so:
- I've cleaned my routing table and removed the two entries referencing eth0, leaving only the loopback destination.
- I have made the connection, and pppd automatically added a new default gateway pointing to the server (10.74.49.22), using the new interface ppp0.
- I have cleaned "/etc/resolv.conf" and trying to access the machines on the remote network by specifying the IP address. At this point I realized that I couldn't even ping the gateway (10.74.49.22)!
Stuck at this point, I've rebooted into Windows, made the connection and looked at the routing table:
===========================================================================
Active Routes:
Network Address Mask Gateway Interface Metric
0.0.0.0 0.0.0.0 10.74.49.117 10.74.49.117 1
10.74.49.22 255.255.255.255 10.74.49.117 10.74.49.117 1
10.74.49.117 255.255.255.255 127.0.0.1 127.0.0.1 50
10.255.255.255 255.255.255.255 10.74.49.117 10.74.49.117 50
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
224.0.0.0 240.0.0.0 10.74.49.117 10.74.49.117 1
255.255.255.255 255.255.255.255 10.74.49.117 10.74.49.117 1
Default gateway: 10.74.49.117
===========================================================================
Here I can ping the server (10.74.49.22) and every machine in the 10.0.0.0/8 network.
Notice that the assigned local address is automatically become the default gateway...
At this point I've reduced the routing table, also removing the default gateway and adding a static route to the destination 10.0.0.0/8 through the gateway 10.74.49.117 (which is the local ip address of the ppp interface assigned to me by the server):
===========================================================================
Active Routes:
Network Address Mask Gateway Interface Metric
10.0.0.0 255.0.0.0 10.74.49.117 10.74.49.117 1
10.74.49.117 255.255.255.255 127.0.0.1 127.0.0.1 50
10.255.255.255 255.255.255.255 10.74.49.117 10.74.49.117 50
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
255.255.255.255 255.255.255.255 10.74.49.117 10.74.49.117 1
===========================================================================
Also with this routing table I can ping all the 10.0.0.0/8 subnet.
So, I've switched back to Linux, made the connection and "copied" the above routing table...
The result? No answer from any remote host.....
This thing is driving me mad!! Oh, I've forgot to say that I haven't setup any firewall and I've tried all the operations with the root user.
I've also tried to look into the transmitted/received packets on the ppp0 device with tcpdump tool, but no packets are TX/RX at all...
Is it possible that the pppd daemon establishes successfully the connection but actually there is some problem with the compression or encryption or something else negotiated with the RAS server?
Sorry for the long post, any help would be REALLY, REALLY appreciated