[LARTC] Info about IFB

[LARTC] Info about IFB

[Samuel Díaz García]

Hi, I'm looking for info about IFB devices and how I can use it to 
incomming traffic shapping.

Has IFB any web about it?
Do any body known where I can find more info about it?

I found this:
http://linux-net.osdl.org/index.php/IFB

But I can't stand fine how to use it to allow many ifb's devices or how 
to use it with "tc actions".

Any help?

Thanks

-- 
    Samuel Díaz García
     Director Gerente
ArcosCom Wireless, S.L.L.

CIF: B11828068
c/ Romero Gago, 19
Arcos de la Frontera
11630 - Cadiz

http://www.arcoscom.com

mailto:samueldg@arcoscom.com
msn: samueldg@arcoscom.com

Móvil: 651 93 72 48
Tlfn.: 956 70 13 15
Fax:   956 70 34 83
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Re: [LARTC] Info about IFB

[Samuel Díaz García]

Any help?

Samuel Díaz García escribió:
> Hi, I'm looking for info about IFB devices and how I can use it to 
> incomming traffic shapping.
> 
> Has IFB any web about it?
> Do any body known where I can find more info about it?
> 
> I found this:
> http://linux-net.osdl.org/index.php/IFB
> 
> But I can't stand fine how to use it to allow many ifb's devices or how 
> to use it with "tc actions".
> 
> Any help?
> 
> Thanks
> 

-- 
    Samuel Díaz García
     Director Gerente
ArcosCom Wireless, S.L.L.

CIF: B11828068
c/ Romero Gago, 19
Arcos de la Frontera
11630 - Cadiz

http://www.arcoscom.com

mailto:samueldg@arcoscom.com
msn: samueldg@arcoscom.com

Móvil: 651 93 72 48
Tlfn.: 956 70 13 15
Fax:   956 70 34 83
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Re: [LARTC] Info about IFB

[Andy Furniss]

Samuel Díaz García wrote:
> Hi, I'm looking for info about IFB devices and how I can use it to 
> incomming traffic shapping.
> 
> Has IFB any web about it?
> Do any body known where I can find more info about it?
> 
> I found this:
> http://linux-net.osdl.org/index.php/IFB
> 
> But I can't stand fine how to use it to allow many ifb's devices or how 
> to use it with "tc actions".
> 
> Any help?
> 
> Thanks
> 

To use many you'll need to specify the number with modprobe -

modprobe ifb numifbs 

ip link ls should show them all - you need to ip link set up dev ifbXX 
aswell.

to send arp coming in on eth0 to ifb19 which has a tbf on it (just to 
see counters - would be silly to really limit arp)

ip link set up ifb19
tc qdisc add dev ifb19 root tbf limit 2k rate 20kbit buffer 2k

tc qdisc add dev eth0 ingress
tc filter add dev eth0 parent ffff: protocol arp prio 1 u32 match u32 0 
0 flowid 1:1 action mirred egress redirect dev ifb19

The flowid 1:1 is what the classification will be when the packet 
returns from the ifb - unless you are shaping again (on a real dev - you 
can't chain ifbs) it doesn't really matter what you put, but you do need 
one as wothout it the rule will be accepted, but won't work (apart from 
as a counter)

look at counters with -

tc -s qdisc ls dev ifb19
tc -s filter ls dev eth0 parent ffff:

If you want to do the same sort of thing on egress you need to put 
something classfull on the interface rather than the default pfifo_fast 
  prio will do.

Some examples show using marks aswell, it's not needed as such and 
doesn't always work as the netfilter bits keep getting out of sync with 
  ifb.

Andy.


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Re: [LARTC] Info about IFB

[ArcosCom Linux User]

I use IMQ to incomming traffic shaping (using u32 to match the
source/destination MACs)

With IMQ I use:

iptables -t mangle -A PREROUTING -i $if_wan0 -j IMQ --to-dev 0

(for example)

To enqueue packets into IMQ device and then shapping.

With IMQ I can use modprobe to set the device count I need and so on.

I really only want to replace IMQ scripts code with IFB, but, at least for
now, I don't stand fine the packet flow using IFB.

I stand now how to initialice ifbX with your example, good!!

Now some aditional question about your example:
   With this line:

tc qdisc add dev ifb19 root tbf limit 2k rate 20kbit buffer 2k

   You are initializing the qdisc for ibf in the same manner you could do
with imq?

   With this lines:
tc qdisc add dev eth0 ingress
tc filter add dev eth0 parent ffff: protocol arp prio 1 u32 match u32 0
0 flowid 1:1 action mirred egress redirect dev ifb19

   Are those analogous as this (my imq0 device as your ifb19 device):
iptables -t mangle -A PREROUTING -i $if_wan0 -j IMQ --to-dev 0

?

   The last, Do I only need add clases and qdiscs to ifb19 as if it where
my imq0 device?


Thanks and sorry for my english.



El Vie, 18 de Agosto de 2006, 11:41, Andy Furniss escribió:
> Samuel Díaz García wrote:
>> Hi, I'm looking for info about IFB devices and how I can use it to
>> incomming traffic shapping.
>>
>> Has IFB any web about it?
>> Do any body known where I can find more info about it?
>>
>> I found this:
>> http://linux-net.osdl.org/index.php/IFB
>>
>> But I can't stand fine how to use it to allow many ifb's devices or how
>> to use it with "tc actions".
>>
>> Any help?
>>
>> Thanks
>>
>
> To use many you'll need to specify the number with modprobe -
>
> modprobe ifb numifbs 
>
> ip link ls should show them all - you need to ip link set up dev ifbXX
> aswell.
>
> to send arp coming in on eth0 to ifb19 which has a tbf on it (just to
> see counters - would be silly to really limit arp)
>
> ip link set up ifb19
> tc qdisc add dev ifb19 root tbf limit 2k rate 20kbit buffer 2k
>
> tc qdisc add dev eth0 ingress
> tc filter add dev eth0 parent ffff: protocol arp prio 1 u32 match u32 0
> 0 flowid 1:1 action mirred egress redirect dev ifb19
>
> The flowid 1:1 is what the classification will be when the packet
> returns from the ifb - unless you are shaping again (on a real dev - you
> can't chain ifbs) it doesn't really matter what you put, but you do need
> one as wothout it the rule will be accepted, but won't work (apart from
> as a counter)
>
> look at counters with -
>
> tc -s qdisc ls dev ifb19
> tc -s filter ls dev eth0 parent ffff:
>
> If you want to do the same sort of thing on egress you need to put
> something classfull on the interface rather than the default pfifo_fast
>   prio will do.
>
> Some examples show using marks aswell, it's not needed as such and
> doesn't always work as the netfilter bits keep getting out of sync with
>   ifb.
>
> Andy.
>
>
> _______________________________________________
> LARTC mailing list
> LARTC@mailman.ds9a.nl
> http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
>


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Re: [LARTC] Info about IFB

[Andy Furniss]

ArcosCom Linux User wrote:
> I use IMQ to incomming traffic shaping (using u32 to match the
> source/destination MACs)
> 
> With IMQ I use:
> 
> iptables -t mangle -A PREROUTING -i $if_wan0 -j IMQ --to-dev 0
> 
> (for example)
> 
> To enqueue packets into IMQ device and then shapping.
> 
> With IMQ I can use modprobe to set the device count I need and so on.
> 
> I really only want to replace IMQ scripts code with IFB, but, at least for
> now, I don't stand fine the packet flow using IFB.

IFB on ingress will hook the packets before netfilter, so you can't use 
iptables to mark or get the denatted addresses like you can with IMQ - 
so it's not a total replacement. There may be a way to do it in the future.

> 
> I stand now how to initialice ifbX with your example, good!!
> 
> Now some aditional question about your example:
>    With this line:
> 
> tc qdisc add dev ifb19 root tbf limit 2k rate 20kbit buffer 2k
> 
>    You are initializing the qdisc for ibf in the same manner you could do
> with imq?

Yes, you set up queues/filters the same as on imq.

> 
>    With this lines:
> tc qdisc add dev eth0 ingress
> tc filter add dev eth0 parent ffff: protocol arp prio 1 u32 match u32 0
> 0 flowid 1:1 action mirred egress redirect dev ifb19
> 
>    Are those analogous as this (my imq0 device as your ifb19 device):
> iptables -t mangle -A PREROUTING -i $if_wan0 -j IMQ --to-dev 0

tc qdisc add dev  $if_wan0 ingress
tc filter add dev $if_wan0 parent ffff: protocol ip ...

would be the same - iptables only sees ip, with ingress filter you can 
do others aswell if you want - all, arp, 8021q or any ethertype protocol 
number (FWIW you need a different prio number for each different 
ethertype filter).

> 
> ?
> 
>    The last, Do I only need add clases and qdiscs to ifb19 as if it where
> my imq0 device?

You'll need to filter aswell - on egress you can use iptables + marks (I 
don't think classify will work). But on ingress you can't use iptables 
because ifb is before netfilter.

Andy.
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