Re: Does -j TOS actually do anything?

Linux Advanced Routing and Traffic Control

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Where did you get the information that setting TOS with
netfilter would affect prio classification ? From what
I can see in the source, prio classifies by skb->priority
which only inheirits a value from tos field during the
forwarding process. I can recall skb->priority also
beeing affected by setsockopt(IP_TOS) (besides SO_PRIORITY)
but not by simply setting the tos field in the ip header.

Best regards,
Patrick

BTW: the netfilter CLASSIFY target from 2.6 or netfiler
patch-o-matic can set skb->priority which is what you need.

Thomas Worthington wrote:

Very simple setup: I have several machines, one of which (192.168.0.198) is used exclusively as a vnc client to a remote site. I want it to get priority over guff like email and web etc.

tc qdisc add dev eth1 root handle 1: prio
tc qdisc add dev eth1 parent 1:1 handle 10: pfifo
tc qdisc add dev eth1 parent 1:2 handle 20: pfifo
tc qdisc add dev eth1 parent 1:3 handle 30: pfifo

iptables -t mangle -I OUTPUT -p icmp -s 192.168.0.198 -j TOS --set-tos 16

Effect: zero. All the vnc traffic from x.198 goes into 1:2.

I've tried all the tables (PREROUTE etc) to no avail. I even tried applying the TOS change to ALL traffice bound for eth1 (the outside line) and still saw no change in the queuing despite tcpdump showing that the tos bits were being set.

Why does this not work? It seems as if the priority is being set before iptables' mangle rules are applied.

Thomas Worthington


_______________________________________________ LARTC mailing list / LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/

[Index of Archives]     [LARTC Home Page]     [Netfilter]     [Netfilter Development]     [Network Development]     [Bugtraq]     [GCC Help]     [Yosemite News]     [Linux Kernel]     [Fedora Users]
  Powered by Linux