Re: Policy routing work in 2.2 but not in 2.4

From: Theodor Milkov (
Date: Sun Jan 20 2002 - 11:55:58 EST

Julian Anastasov wrote:

> He-he, it seems you can't use the lower 2 bits:
> linux/include/net/route.h:#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
> From routes.c:ip_route_input():
> tos &= IPTOS_RT_MASK;
>>The configuration I am referring to used to work absolutely perfect with
>>kernel versions between 2.2.5 and 2.2.20 for more than an year.
> In 2.2 it is:
> tos &= IPTOS_TOS_MASK;
> What to say, the standards change. But I'm not sure, ask
> the maintainers. What I see is that 2.4 ignores the lower 2 bits
> from the user defined tos. Check the ECN support.

You are absolutely right. When I use tos value of 0x08 instead of 0x02
routing works as expected. Brr... tos 0x02 is well known Type Of Service
  as defined in /usr/src/linux/include/linux/ip.h:

#define IPTOS_MINCOST 0x02

Can someone of the network support maintainers to enlighten us please?

Best regards,
Theodor Milkov

To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to
More majordomo info at

This archive was generated by hypermail 2b29 : Wed Jan 23 2002 - 21:01:13 EST