any good linux packet generator tools?

Hi, Guru:

I want a linux packet generator tool to generate IP packets and
manipulate ethernet header, IP header and TCP/UDP headers, also better
have capture function, which could tell me what kind of packet I
received. It's should be command line tools, no need GUI. also, I do
not mind it is multiple applications, any good tools recommend? thanks
in advance.

/zhenwu

(E-Mail Removed) wrote:
> Hi, Guru:
>
> I want a linux packet generator tool to generate IP packets and
> manipulate ethernet header, IP header and TCP/UDP headers, also better
> have capture function, which could tell me what kind of packet I
> received. It's should be command line tools, no need GUI. also, I do
> not mind it is multiple applications, any good tools recommend? thanks
> in advance.

hping to generate.
tcpdump to receive.