[lwip-users] TAP/TUN Device

[Dinesh Chachan]

As Kieran had said to enable IP fowarding. It has already been enabled in my system. I even ried to run the simhost application. But the simhost application doesnot respond to any ping messages.

The configuration of my tun devices is as follows

tun0      Link encap:Point-to-Point Protocol
          inet addr:192.168.1.2  P-t-P:192.168.1.3  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:10
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

tun1      Link encap:Point-to-Point Protocol
          inet addr:192.168.1.3  P-t-P:192.168.1.2  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:1 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:10
          RX bytes:44 (44.0 b)  TX bytes:0 (0.0 b)

On tun0 my server program is listening while on tun1 my client program is writing data.

When I do tcpdump -i tun0 nothing is shown

When I do tcpdump -i tun1 the following is displayed

tcpdump: listening on tun1
14:04:26.454185 192.168.1.3.4097 > 192.168.1.2.1500: S 6509:6509(0) win 1024 <ms
s 128> (DF)
14:04:29.477613 192.168.1.3.4097 > 192.168.1.2.1500: S 6509:6509(0) win 1024 <ms
s 128> (DF)
14:04:32.501040 192.168.1.3.4097 > 192.168.1.2.1500: S 6509:6509(0) win 1024 <ms
s 128> (DF)
14:04:35.524490 192.168.1.3.4097 > 192.168.1.2.1500: S 6509:6509(0) win 1024 <ms
s 128> (DF)
tcpdump: pcap_loop: recvfrom: Network is down

And my client program ends with netconn_connect returning an error value -3.

Am I doing something wrong?