Send IP traffic to own IP address over first router/gateway

Hello,

I try to evaluate the performance of the link between a linux box with
one NIC and the first router/gateway (using ping, ftp, ...).

The problem: all sent IP packets to own IP address are routed local in
the box.

How is it possible to patch the kernel or modify the routing tables
that packets to own IP address treated like packets to destinations
behind the gateway/router?

Thanks.

Best wishes.

Achim

Achim wrote:
> Hello,
>
> I try to evaluate the performance of the link between a linux box with
> one NIC and the first router/gateway (using ping, ftp, ...).
>
> The problem: all sent IP packets to own IP address are routed local in
> the box.
>
> How is it possible to patch the kernel or modify the routing tables
> that packets to own IP address treated like packets to destinations
> behind the gateway/router?
>
> Thanks.
>
> Best wishes.
>
> Achim

Hi Achim,

there was a thread starting on April 22nd 2004, initiated by
"kenji_matsumoto@mail.goo.ne.jp"
"pinging between two NIC on my PC"

there was a second thread starting on May 7th 2004, initiated by
"frank19991@hotmail.com"
"How to send packets out and come back ?"

Try to find those threads with 'google' and follow the the
discussions over there.

Toni
(I made some suggestions for both threads)

Toni Erdmann <for-spammers-only@web.de> wrote in message news:<cbpdhd$e5o$1@news.mch.sbs.de>...
>
> Hi Achim,
>
> there was a thread starting on April 22nd 2004, initiated by
> "kenji_matsumoto@mail.goo.ne.jp"
> "pinging between two NIC on my PC"
>
> there was a second thread starting on May 7th 2004, initiated by
> "frank19991@hotmail.com"
> "How to send packets out and come back ?"

Hello Toni,

I had already read these two threads, but didn't find a solution to my
problem:

I try to ping my own IP address with one NIC over the first router:
ping -I eth0 <IP of eth0>
Route added before:
route add -host <IP of eth0> gw <IP of R>
The ping is local.
In the routing table local exists an entry for the IP of eth0,
indicated as local.
If I delete this route <local IP of eth0> in table local the ping
fails with
connect: Invalid argument
because there is no route to eth0.

I think we need a kernel patch to prevent local looping of IP packets
destined to own IP address . This is the first step: to get the packet
out of the box.

The second step is to get the packet from the Router and to prevent
dropping (this is the kernel patch deleting two lines).

Any ideas to take step 1?

Thanks,

Achim

Achim wrote:
> Toni Erdmann <for-spammers-only@web.de> wrote in message news:<cbpdhd$e5o$1@news.mch.sbs.de>...
>
>>Hi Achim,
>>
>>there was a thread starting on April 22nd 2004, initiated by
>>"kenji_matsumoto@mail.goo.ne.jp"
>>"pinging between two NIC on my PC"
>>
>>there was a second thread starting on May 7th 2004, initiated by
>>"frank19991@hotmail.com"
>>"How to send packets out and come back ?"
>
>
> Hello Toni,
>
> I had already read these two threads, but didn't find a solution to my
> problem:
>
> I try to ping my own IP address with one NIC over the first router:
> ping -I eth0 <IP of eth0>

So you're trying to ping yourself with only one NIC ?

> Route added before:
> route add -host <IP of eth0> gw <IP of R>
> The ping is local.
> In the routing table local exists an entry for the IP of eth0,
> indicated as local.
> If I delete this route <local IP of eth0> in table local the ping
> fails with
> connect: Invalid argument
> because there is no route to eth0.
>
> I think we need a kernel patch to prevent local looping of IP packets
> destined to own IP address . This is the first step: to get the packet
> out of the box.
>
> The second step is to get the packet from the Router and to prevent
> dropping (this is the kernel patch deleting two lines).
>
> Any ideas to take step 1?

No, we always used at least 2 NICs (ppp0 and eth0 or eth[01])

Did you try to find something from "Ben Greear" in 'linux.kernel' or
'linux.networking' (right name?). I guess, he posted a lot to both
lists.

Toni