iptables precedence bits

Hi,

How to set precedence bits using iptables. I want to set TOS Bits to
0x20. How can I do this ? I don't find any mnemonics for this hex value.


Regards,
Tejas Kokje

"Tejas Kokje" <(E-Mail Removed)> wrote in message
news(E-Mail Removed)...
> Hi,
>
> How to set precedence bits using iptables. I want to set TOS Bits to
> 0x20. How can I do this ? I don't find any mnemonics for this hex value.

The syntax is:
-m tos --tos mnemonic [other-args] -j target

You can use iptables -m tos -h to see the list of allowed names.

Hope this help.

mm

Yes,

But iptables only allows to set those 5 mnemonics. What if I want
to set one of the top three TOS bits of IP header. I mean out of 8
TOS bits i want to set third bit. i.e. 00100000. (priority bit).

I guess I will have to revert to good old ipchains

Regards,
Tejas Kokje
University of Southern California
Los Angeles

On Fri, 02 Jul 2004 10:03:10 +0200, Michael Meckelein wrote:

>
> "Tejas Kokje" <(E-Mail Removed)> wrote in message
> news(E-Mail Removed)...
>> Hi,
>>
>> How to set precedence bits using iptables. I want to set TOS Bits to
>> 0x20. How can I do this ? I don't find any mnemonics for this hex value.
>
> The syntax is:
> -m tos --tos mnemonic [other-args] -j target
>
> You can use iptables -m tos -h to see the list of allowed names.
>
> Hope this help.
>
> mm

"Tejas Kokje" <(E-Mail Removed)> wrote in message
news(E-Mail Removed)...
> Yes,
>
> But iptables only allows to set those 5 mnemonics. What if I want
> to set one of the top three TOS bits of IP header. I mean out of 8
> TOS bits i want to set third bit. i.e. 00100000. (priority bit).
>

I know I have read some time ago about bit manipulation. Maybe this tutorial
is interessting for you. But I am not sure if it fits to your requirements.
http://www.sans.org/rr/special/iptables_u32.pdf

mm