curl-loader-devel

how does curl-loader use RTNETLINK

[Javier M. <jam...@in...>]

Hi, first thanks for your excellent program, very useful.
I have some questions about the use of sockets.
When I load a client with a virtual IP I understand curl-loader uses
RTNETLINK for this, and when I run it again with the same config file
(same client ip) appears the following:

add_secondary_ip_addrs - setting secondary IP 10.111.111.150
rtnl_talk(): RTNETLINK answers: File exists
add_secondary_ip_addrs - note: probably, the IP-address
"10.111.111.150/24" already exists.

this is not really a problem when using the loader, but when I use the
same ip used by another machine (e.g. a virtual machine), the virtual
client replaces it (supplanting) and the host became unreachable (even
when curl-loader is down).
Do you know how to delete the file which is referenced by rtnl_talk()
?, or if there is another way to solve this problem.

thanks very much for your help.

greetings from chile!!

-- 
Javier Miranda
jam...@in...
+569 8-552-6707

Re: how does curl-loader use RTNETLINK

[Robert I. <cor...@gm...>]

Hi Javier,

On Feb 20, 2008 7:32 PM, Javier Miranda <jam...@in...> wrote:

> add_secondary_ip_addrs - setting secondary IP 10.111.111.150
> rtnl_talk(): RTNETLINK answers: File exists


This means, that the secondary IP-address has been already
added to the interface, thus, it will be re-used

>
> add_secondary_ip_addrs - note: probably, the IP-address
> "10.111.111.150/24" already exists.
>
> this is not really a problem when using the loader, but when I use the
> same ip used by another machine (e.g. a virtual machine), the virtual
> client replaces it (supplanting) and the host became unreachable (even
> when curl-loader is down).


Why to use the same IP? Y can use any IP-addresses, from any networks,
just ensure routing.


> Do you know how to delete the file which is referenced by rtnl_talk()
> ?, or if there is another way to solve this problem.


Sure. The command ip is your friend:
like # ip addr del .....
look at #man ip

Sincerely,
Robert Iakobashvili
"Light will come from Jerusalem"
...........................................................
http://curl-loader.sourceforge.net
An open-source web testing and traffic generation.

Re: how does curl-loader use RTNETLINK

[Javier M. <jam...@in...>]

Ok, thanks for your fast reply!
However, It would be useful that the loader, once when it has
finished, could close or delete the secondary ip that assigns to the
interface.
Additionally, it would be very helpul for me if you tell me how the
loader allocates those directions and more especifically, how the
server knows where to send back the responses to the virtual clients,
since i have manually ping'ed the clients from the server without no
response.
Sincerely,

On 2/20/08, Robert Iakobashvili <cor...@gm...> wrote:
> Hi Javier,
>
> On Feb 20, 2008 7:32 PM, Javier Miranda <jam...@in...> wrote:
>
> > add_secondary_ip_addrs - setting secondary IP 10.111.111.150
> > rtnl_talk(): RTNETLINK answers: File exists
>
> This means, that the secondary IP-address has been already
>  added to the interface, thus, it will be re-used
> >
> > add_secondary_ip_addrs - note: probably, the IP-address
> > "10.111.111.150/24" already exists.
> >
> > this is not really a problem when using the loader, but when I use the
> > same ip used by another machine (e.g. a virtual machine), the virtual
> > client replaces it (supplanting) and the host became unreachable (even
> > when curl-loader is down).
>
> Why to use the same IP? Y can use any IP-addresses, from any networks,
> just ensure routing.
>
>
> >
> > Do you know how to delete the file which is referenced by rtnl_talk()
> > ?, or if there is another way to solve this problem.
>
>
> Sure. The command ip is your friend:
> like # ip addr del .....
> look at #man ip
>
> Sincerely,
> Robert Iakobashvili
> "Light will come from Jerusalem"
> ...........................................................
>  http://curl-loader.sourceforge.net
> An open-source web testing and traffic generation.
> -------------------------------------------------------------------------
>  This SF.net email is sponsored by: Microsoft
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>
>


-- 
Javier Miranda
jam...@in...
8-552-6707

Re: how does curl-loader use RTNETLINK

[Robert I. <cor...@gm...>]

Javier,

On Thu, Feb 21, 2008 at 2:33 PM, Javier Miranda <jam...@in...>
wrote:

> Ok, thanks for your fast reply!
> However, It would be useful that the loader, once when it has
> finished, could close or delete the secondary ip that assigns to the
> interface.


Agree. Y may wish to provide the patches for integration

>
> Additionally, it would be very helpul for me if you tell me how the
> loader allocates those directions and more especifically, how the
> server knows where to send back the responses to the virtual clients,
> since i have manually ping'ed the clients from the server without no
> response.


curl-loader allocated ip-addresses via netlink as the secondary addresses
and binds each virtual client to an address. Another option described in
FAQs is
to use the same ip-address for all clients and it could be an existing
address.

When you are ping-ing it goes by default thru the routing table.

ping with option -I  (capital I is for Interface) will make pin-ing via the
interface or IP-address, that follows:

#ping -I 192.168.1.100 192.168.1.1
send ICMP ECHO packet to the host/gateway 192.168.1.1 via ip-address
192.168.1.100 and not via
the routing table definitions.

Sincerely,
Robert Iakobashvili
"Light will come from Jerusalem"
...........................................................
http://curl-loader.sourceforge.net
An open-source web testing and traffic generation.