On Tue, 03 Apr 2007 23:46:56 +0000, Walter Roberson wrote:

> In article <1175607526.159882.159740@l77g2000hsb.googlegroups .com>,
> lostlander <lostlander.tom@gmail.com> wrote:
>>Why most TCP/IP implementations are designed to allow sending packets
>>whose src IP or Mac adderss is not the sender's real address?! In my
>>opinion, this causes many problems, especially lead to some virus.
>

(snip)

5) It allows for truly transparent proxies.

6) It allows security professionals to test security. The bad guys will
find some method even if the OS normally doesn't allow it.

M4