Re: [Discuss-gnuradio] TunTap Interace for GNU Radio IEEE 802.11 a/g/p module

[Bastian Bloessl]

Hi,

On 10/19/2017 02:49 AM, Wen Cui wrote:
> I followed the nic.sh file and your replies to others in the mail list. I 
> really want to know whether it is only related to the TUN/TAP setup thing or it 
> is related to the gnuradio code. I don’t know how to figure out the setup 
> problem of the transceiver and where is the good place to ask this question. If 
> you'd like to give me a hint, I will really appreciate about that.
>   
> PC1:
> //wireless card in PC1
> Tap0, IP: 192.168.123.1 MAC: 12:34:56:78:90:ab
> wls5, IP: 192.168.123.20 MAC: a8:96:8a:f6:d5:2e
>
> //USRP connected the PC1 through Ethernet cable
> enp10s0, IP: 192.168.10.100 MAC: 40:6a:7f:bc:f2:2f
> USRP, IP: 192.168.10.5 MAC: 00:80:2f:0a:cf:68
>
> PC2:
> //wireless card in PC2
> wlp8s0, IP:192.168.123.50 MAC: 74:e7:0f:34:42:ba
>
> I did the same config code as nic.sh does in PC1 but with changed IP and MAC 
> address. I also set the arp and route things in PC2.
>
> After I turn the tap0 up in PC1, I cannot PING PC1 anymore through PC2, and 
> vice versa. The PC1 can hear the ICMP request from PC2, but cannot reply for 
> that.

If both PCs can send a ping, but both don't trigger a reply, it might 
just be that ICMP requests are ignored.

This can be changed with:

echo 0 > /proc/sys/net/ipv4/icmp_echo_ignore_all

If that's not the problem, start Wireshark on both sender and receiver 
and monitor the TUN/TAP interface only to better understand what's 
really going on. Maybe a frame is sent, but not received by the SDR or 
something like that.

Best,
Bastian