Re: weird ip sequence number

[Richard B. Johnson]

On Mon, 18 Feb 2002, Xinwen - Fu wrote:

> Hi,
> 	Really weird!
> 
> 	I have two linux machines with kernel 2.4.17. When I ping one
> machine from the other machine, all the ping request ip packets have the
> same sequnce number 0. The ping reply packets have different ip
> sequence numbers. Moreover, when I send udp packets using general
> socket programming, all the udp packets have the same sequence number 0.
> 
> 	I use ethereal to check the packets.
> 
> 	What's the problem?
> 
> 	Thanks!
> 

The sequence numbers for 'ping' come from ping. They are not generated
by the kernel.

`strace` [snipped]
sendto(3, "\10\0\335\360\360T\0\0@^q<\202\34\v\0\10\t\n\v\f\r\16\17"...,
                              |________ sequence NR

sendto(3, "\10\0\237\v\360T\1\0A^q<\277\1\v\0\10\t\n\v\f\r\16\17\20"...,
                            |___________ sequence NR

Cheers,
Dick Johnson

Penguin : Linux version 2.4.1 on an i686 machine (797.90 BogoMips).

    I was going to compile a list of innovations that could be
    attributed to Microsoft. Once I realized that Ctrl-Alt-Del
    was handled in the BIOS, I found that there aren't any.