Send UDP packet with specific source port

[susu6514]

Hi

I'm doing some test and want to mimicry a DNS behavior but I find I can't use a specific port when sending UDP packet.

The behavior is like this.

PCA sends DNS query to PCB (UDP port 1234 to 53)

PCB sends back DNS reply to PCA (UDP port 53 to 1234)

Is there a way to do this?

Thank you.

Edited October 14, 2010 by susu6514

[PsaltyDS]

UDPOpen(), UDPSend()

Dog ate your help file?

[martin]

UDPOpen(), UDPSend()

Dog ate your help file?

Or maybe the dog is writing the program for you using an old version of AutoIt?

[PsaltyDS]

Oh, wow. Is that "UDP port 1234 to 53" really old AutoIt syntax?

I wouldn't know, 'cause I'm so much YOUNGER than martin!

[martin]

I wouldn't know, 'cause I'm so much YOUNGER than martin!

Yes, .. most people are . But I've still good a good memory.

And the other thing is, I've still got a good memory.

[Richard Robertson]

What you are trying to do won't work using AutoIt's build in UDP commands. They only let you specify the destination port and not the source port on your outgoing data.

You'll have to make some DllCalls to do this.

[martin]

In my earlier post I think I was thinking of this.

So maybe you could arrange things like this.

Send a udp message from the PC to the PCA port 1234. (I don't know what PCA means!) Then the program on PCA could work out what port was used on the PC and use that port instead of 53.

[Richard Robertson]

Martin, that's PC (personal computer) 'A' and PC 'B'. At least that was my understanding.

Also, setting the UDP source port is doable. Just not in pure AutoIt.

Edited October 14, 2010 by Richard Robertson

[susu6514]

Thank you, Martin. Maybe I should use WinPcap instead.

Edited October 15, 2010 by susu6514