Any simple tools can help me to test IP session?

Question

Statement of the Problem:

I have a iOS project about establishing IP session to a hardware IP host. The hardware suppose to response my iOS app, only if the app send correct IP packet. However, the hardware is also developing by other team. I can't make the hardware in debug mode at the moment. But I can use Wireshark to capture IP packets.

Problem is I can't trigger any of GCDAsyncSocket or AsyncUdpSocket's TCP UDP delegate protocol functions. Like:

- (void)onUdpSocket:(AsyncUdpSocket *)sock didNotSendDataWithTag:(long)tag dueToError:(NSError *)error

Question:

Is there any tools can aid me to manually response a IP packet after receiving App IP packet from iOS App? I need verify my iOS Code is OK or not.

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Edit:
I forgot mention that I have used Netcat to receive packets:

 nc -4 -u -l 80

However, It cannot reply me anything.

Answer 1

I would recommend taking a look at Scapy. You should be able to build response packets for most of the network protocol types (Layer4/Layer3/Layer2).

URL: http://theitgeekchronicles.files.wordpress.com/2012/05/scapyguide1.pdf