HOw to send and receive packets in grc?

We can send and receive data using USRP in grc, but what if we want to
do the same in packet format? Like I am working with some pre recorded
USRP file and want to see all packet I am receiving from it that what is
the procedure. I have created packet sniffer in java but no idea how to
work in grc.

Thanks.

You will need an IP layer on top of gnu radio to introduce the notion of
IP
packets. Luckily there is an easy way to do it in linux using tunneling

i.e. via the dev/tun interface. Read more about it (uncle google knows
where information can be found).

As an example, you can look at examples/ofdm/tunnel.py but there’s a
few
things that are missing there. The configuration can be a bit tricky.
You
will have to configure the tun device and allow for local packets to be
delivered with remote IP addresses in the IP header. I forgot how to do
this already but there’s a setting in the proc file system to do this.
Otherwise, the kernel will drop such packets.

Also, do not expect ICMP to work.