Complicated networking problem

Complicated networking problem

[Jarne Cook]

Hello all

(I am not subscribed. Please CC me)

Please forgive me if I have posed this message in the wrong place.  I have 
been searching for the answer for days with no resolve.

The question is: 

How do I get eth0 and wlan0 both working together.  

They are both using dhcp to the same simple network.  That's right.  Same 
network.  They both end up with gateway=192.168.0.1, netmask=255.255.255.0.  
But ofcourse they do not have the same IP addresses.

I dont know if this matters but im using ISC's dhclient3.

This is what it looks like when wlan0 is brought up, followed by eth0.
------------------------------------------------------------------------------
i8600:~# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:11:43:5F:E7:1D
          inet addr:192.168.0.238  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::211:43ff:fe5f:e71d/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:277 errors:0 dropped:0 overruns:0 frame:0
          TX packets:60 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:24784 (24.2 KiB)  TX bytes:9278 (9.0 KiB)
          Interrupt:11
------------------------------------------------------------------------------
i8600:~# ifconfig wlan0
wlan0     Link encap:Ethernet  HWaddr 00:11:F5:0C:D9:A3
          inet addr:192.168.0.202  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::211:f5ff:fe0c:d9a3/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1538 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1085 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:203213 (198.4 KiB)  TX bytes:130588 (127.5 KiB)
          Interrupt:7 Memory:faff6000-faff7fff
------------------------------------------------------------------------------
i8600:~# ip rule list
0:      from all lookup local
32766:  from all lookup main
32767:  from all lookup default
------------------------------------------------------------------------------
i8600:~# ip route list table local
local 192.168.0.238 dev eth0  proto kernel  scope host  src 192.168.0.238
broadcast 192.168.0.255 dev wlan0  proto kernel  scope link  src 192.168.0.202
broadcast 192.168.0.255 dev eth0  proto kernel  scope link  src 192.168.0.238
broadcast 127.255.255.255 dev lo  proto kernel  scope link  src 127.0.0.1
local 192.168.0.202 dev wlan0  proto kernel  scope host  src 192.168.0.202
broadcast 192.168.0.0 dev wlan0  proto kernel  scope link  src 192.168.0.202
broadcast 192.168.0.0 dev eth0  proto kernel  scope link  src 192.168.0.238
broadcast 127.0.0.0 dev lo  proto kernel  scope link  src 127.0.0.1
local 127.0.0.1 dev lo  proto kernel  scope host  src 127.0.0.1
local 127.0.0.0/8 dev lo  proto kernel  scope host  src 127.0.0.1
------------------------------------------------------------------------------
i8600:~# ip route list table main
192.168.0.0/24 dev wlan0  proto kernel  scope link  src 192.168.0.202
192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.238
default via 192.168.0.1 dev eth0
default via 192.168.0.1 dev wlan0
------------------------------------------------------------------------------
i8600:~# ip route list table default
------------------------------------------------------------------------------
i8600:~# iptables-save
------------------------------------------------------------------------------


So.
Is there a way to allow an application which has bound to wlan0 
(192.168.0.202) and an application bound to eth0 (192.168.0.238) both have 
access to the internet at the same time, and not require an application to 
bind to a different local address?

Thanks

Jarne

-- 
Jarne Cook <jcook@siliconriver.com.au>
Siliconriver.com.au

Re: Complicated networking problem

[Robert Hancock]

Jarne Cook wrote:
> Is there a way to allow an application which has bound to wlan0 
> (192.168.0.202) and an application bound to eth0 (192.168.0.238) both have 
> access to the internet at the same time, and not require an application to 
> bind to a different local address?

I'm not sure exactly what you want to have happen here.. if an 
application is making outbound connections it has to effectively use one 
interface or the other. If you want to switch between the two of them 
automatically, something like 
NetworkManager(http://people.redhat.com/dcbw/NetworkManager/) may work, 
however it's not going to be seamless (as in, preserving open 
connections), since the IP addresses are different..

-- 
Robert Hancock      Saskatoon, SK, Canada
Home Page: http://www.roberthancock.com/

Re: Complicated networking problem

[Valdis.Kletnieks]

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On Mon, 28 Feb 2005 14:59:31 +1000, Jarne Cook said:

> They are both using dhcp to the same simple network.  That's right.  Same 
> network.  They both end up with gateway=192.168.0.1, netmask=255.255.255.0.  
> But ofcourse they do not have the same IP addresses.

I don't suppose your network people would be willing to change it thusly:

wired ports:  gateway 192.168.0.1, netmask 255.255.255.128.0
wireless:     gateway 192.168.128.1, netmask 255.255.255.128.0

Or move the wireless up to 192.168.1.1 if they think that would confuse things
too much.

There's a limit to how far we should bend over backwards to support stupid
networking decisions. 192.168 *is* a /16, might as well use it. ;)

If they won't, you're pretty much stuck with binding applications to one
interface or another.

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Re: Complicated networking problem

[Dmitry Torokhov]

On Monday 28 February 2005 21:02, Valdis.Kletnieks@vt.edu wrote:
> On Mon, 28 Feb 2005 14:59:31 +1000, Jarne Cook said:
> 
> > They are both using dhcp to the same simple network.  That's right.  Same 
> > network.  They both end up with gateway=192.168.0.1, netmask=255.255.255.0.  
> > But ofcourse they do not have the same IP addresses.
> 
> I don't suppose your network people would be willing to change it thusly:
> 
> wired ports:  gateway 192.168.0.1, netmask 255.255.255.128.0
> wireless:     gateway 192.168.128.1, netmask 255.255.255.128.0
> 
> Or move the wireless up to 192.168.1.1 if they think that would confuse things
> too much.
> 
> There's a limit to how far we should bend over backwards to support stupid
> networking decisions. 192.168 *is* a /16, might as well use it. ;)
> 
> If they won't, you're pretty much stuck with binding applications to one
> interface or another.
> 

If the goal is to primarily use wired link and seamlessly swith to wireless
then look into bonding driver in failover mode with wired interface as 
primary. This way you have only one address and userspace does not notice
anything.
 
-- 
Dmitry

Re: Complicated networking problem

[Jarne Cook]

On Tuesday 01 March 2005 12:35, you wrote:
> On Monday 28 February 2005 21:02, Valdis.Kletnieks@vt.edu wrote:
> > On Mon, 28 Feb 2005 14:59:31 +1000, Jarne Cook said:
> > > They are both using dhcp to the same simple network.  That's right. 
> > > Same network.  They both end up with gateway=192.168.0.1,
> > > netmask=255.255.255.0. But ofcourse they do not have the same IP
> > > addresses.
> >
> > I don't suppose your network people would be willing to change it thusly:
> >
> > wired ports:  gateway 192.168.0.1, netmask 255.255.255.128.0
> > wireless:     gateway 192.168.128.1, netmask 255.255.255.128.0
> >
> > Or move the wireless up to 192.168.1.1 if they think that would confuse
> > things too much.
> >
> > There's a limit to how far we should bend over backwards to support
> > stupid networking decisions. 192.168 *is* a /16, might as well use it. ;)
> >
> > If they won't, you're pretty much stuck with binding applications to one
> > interface or another.
>
> If the goal is to primarily use wired link and seamlessly swith to wireless
> then look into bonding driver in failover mode with wired interface as
> primary. This way you have only one address and userspace does not notice
> anything.

Damn

Having to configure the interfaces using bonding was not really the answer I 
was expecting.

I did not think linux would be that rigid.  I figured if poodoze is able to do 
it (seamlessly mind you), surely linux (with some tinkering) would be able to 
do it also.

The goal was to have the networking on the laptop work as perfectly as 
crapdoze does.  

Perhaps I should and this topic to my list of software issues that no-one else 
cares about. "man that list is getting big".  maybe one day I'll develop the 
balls to get deep into the code.

-- 
Jarne Cook <jcook@siliconriver.com.au>
Siliconriver.com.au

Re: Complicated networking problem

[Jarne Cook]

On Tuesday 01 March 2005 12:35, you wrote:
> On Monday 28 February 2005 21:02, Valdis.Kletnieks@vt.edu wrote:
> > On Mon, 28 Feb 2005 14:59:31 +1000, Jarne Cook said:
> > > They are both using dhcp to the same simple network.  That's right. 
> > > Same network.  They both end up with gateway=192.168.0.1,
> > > netmask=255.255.255.0. But ofcourse they do not have the same IP
> > > addresses.
> >
> > I don't suppose your network people would be willing to change it thusly:
> >
> > wired ports:  gateway 192.168.0.1, netmask 255.255.255.128.0
> > wireless:     gateway 192.168.128.1, netmask 255.255.255.128.0
> >
> > Or move the wireless up to 192.168.1.1 if they think that would confuse
> > things too much.
> >
> > There's a limit to how far we should bend over backwards to support
> > stupid networking decisions. 192.168 *is* a /16, might as well use it. ;)
> >
> > If they won't, you're pretty much stuck with binding applications to one
> > interface or another.
>
> If the goal is to primarily use wired link and seamlessly swith to wireless
> then look into bonding driver in failover mode with wired interface as
> primary. This way you have only one address and userspace does not notice
> anything.

Damn

Having to configure the interfaces using bonding was not really the answer I 
was expecting.

I did not think linux would be that rigid.  I figured if poodoze is able to do 
it (seamlessly mind you), surely linux (with some tinkering) would be able to 
do it also.

The goal was to have the networking on the laptop work as perfectly as 
crapdoze does.  

Perhaps I should and this topic to my list of software issues that no-one else 
cares about. "man that list is getting big".  maybe one day I'll develop the 
balls to get deep into the code.


-- 
Jarne Cook <jcook@siliconriver.com.au>
Siliconriver.com.au

Re: Complicated networking problem

[Kyle Moffett]

On Mar 01, 2005, at 22:27, Jarne Cook wrote:
> Damn
>
> Having to configure the interfaces using bonding was not really the 
> answer I
> was expecting.
>
> I did not think linux would be that rigid.  I figured if poodoze is 
> able to do
> it (seamlessly mind you), surely linux (with some tinkering) would be 
> able to
> do it also.
>
> The goal was to have the networking on the laptop work as perfectly as
> crapdoze does.
>
> Perhaps I should and this topic to my list of software issues that 
> no-one else
> cares about. "man that list is getting big".  maybe one day I'll 
> develop the
> balls to get deep into the code.

Well, what exactly is the desired behavior for you?  If you have two 
network
interfaces to the same local network, the default config will pick a 
random
one (They're both equal-cost unless you tell it otherwise) and send 
ARPs and
everything else through that one interface.  If you take it down, it may
require a minute or so to update the rest of the network to the new 
hardware
address, but eventually they will figure it out.  I suppose if that is 
the
expected config, you could tell the box to send out a gratuitous ARP 
packet
when you reconfigure interfaces, but that's a userspace issue in any 
case.

As far as networking is concerned, a subnet is an atomic networking 
unit.
Everything on it is considered directly and equally attached to 
everything
else, unless informed otherwise via a switch protocol.  Any system that
doesn't follow that rule is broken.

Cheers,
Kyle Moffett

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------END GEEK CODE BLOCK------

Re: Complicated networking problem

[Daniel Gryniewicz]

On Wed, 2005-03-02 at 13:27 +1000, Jarne Cook wrote:
>On Tuesday 01 March 2005 12:35, you wrote:
>> On Monday 28 February 2005 21:02, Valdis.Kletnieks@vt.edu wrote:
>> > On Mon, 28 Feb 2005 14:59:31 +1000, Jarne Cook said:
>> > > They are both using dhcp to the same simple network.  That's right. 
>> > > Same network.  They both end up with gateway=192.168.0.1,
>> > > netmask=255.255.255.0. But ofcourse they do not have the same IP
>> > > addresses.
>> >
>> > I don't suppose your network people would be willing to change it thusly:
>> >
>> > wired ports:  gateway 192.168.0.1, netmask 255.255.255.128.0
>> > wireless:     gateway 192.168.128.1, netmask 255.255.255.128.0
>> >
>> > Or move the wireless up to 192.168.1.1 if they think that would confuse
>> > things too much.
>> >
>> > There's a limit to how far we should bend over backwards to support
>> > stupid networking decisions. 192.168 *is* a /16, might as well use it. ;)
>> >
>> > If they won't, you're pretty much stuck with binding applications to one
>> > interface or another.
>>
>> If the goal is to primarily use wired link and seamlessly swith to wireless
>> then look into bonding driver in failover mode with wired interface as
>> primary. This way you have only one address and userspace does not notice
>> anything.
>
>Damn
>
>Having to configure the interfaces using bonding was not really the answer I 
>was expecting.
>
>I did not think linux would be that rigid.  I figured if poodoze is able to do 
>it (seamlessly mind you), surely linux (with some tinkering) would be able to 
>do it also.
>
>The goal was to have the networking on the laptop work as perfectly as 
>crapdoze does.  
>
>Perhaps I should and this topic to my list of software issues that no-one else 
>cares about. "man that list is getting big".  maybe one day I'll develop the 
>balls to get deep into the code.
>
>

Check out NetworkManager.  It will do what you want.

Daniel