Hey all, I've been running a dual boot FC3 and xp system for quite some
time, in fact the only reason i think my xp system has survived for so
long is because i don't let xp on the net except to update malware data
files, however:

when i enable the network interface in xp and subsequently reboot into
linux, the ifup script either fails or gives me a local ip address
(something like 192.) and my linux system can't get onto the internet.
It's pretty annoying and it happens whether i disable the network device
under windows before rebooting or not.

If i can catch it early enough in the boot process i can usually pull the
power on the modem, forcing it to do a reset. After which it works but i'm
beginning to wonder if that's particularly healthy for the modem... So,
although i know the fault is probably with windows (i thought maybe it
doesn't release the dhcp address too readily) any thoughts on how to
remedy the situation?

Kind Regards.

aq wrote:
> Hey all, I've been running a dual boot FC3 and xp system for quite
some
> time, in fact the only reason i think my xp system has survived for
so
> long is because i don't let xp on the net except to update malware
data
> files, however:
>
> when i enable the network interface in xp and subsequently reboot
into
> linux, the ifup script either fails or gives me a local ip address
> (something like 192.) and my linux system can't get onto the
internet.
> It's pretty annoying and it happens whether i disable the network
device
> under windows before rebooting or not.
>
> If i can catch it early enough in the boot process i can usually pull
the
> power on the modem, forcing it to do a reset. After which it works
but i'm
> beginning to wonder if that's particularly healthy for the modem...
So,
> although i know the fault is probably with windows (i thought maybe
it
> doesn't release the dhcp address too readily) any thoughts on how to
> remedy the situation?

Two vital pieces of info you left out -- like what brand/model (CM/dsl)
modem and the name of your service provider/ISP.

Sounds like your modem is cacheing client identifiers and Windows
usually does it differently from Linux. There are several other
posibilities but hard to guess what without the info.

You can use ethereal to inspect the dhcp packets being passed in a
lease request by running it, then requesting a new lease. Obviously
you can't use it at boot. It runs equally well on XP as Linux and
capture files from one work in the other.

In any case, there is some item that is different in the XP request
from the Linux request, and since unplugging the modem can "work" I
suspect the modem is cacheing this info before it is ever sent
upstream. No way to know without spec sheets/technical manuals or
sniffing the wire.

You might also look here for guidance if it is a provider quirk:
http://www.dslreports.com/

Here is an explanation of client-id differences. Note that some ISPs
will not give out a new lease when quickly changing them -- like
re-booting. Some just give out different IPs.
http://homepage.ntlworld.com/robin.d...html#dhcpmulti
hth,
prg
email above disabled

On Wed, 12 Jan 2005 20:44:05 -0800, prg wrote:


> aq wrote:
<snip>
>> when i enable the network interface in xp and subsequently reboot
> into
>> linux, the ifup script either fails or gives me a local ip address
>> (something like 192.) and my linux system can't get onto the
> internet.
>> It's pretty annoying and it happens whether i disable the network
> device
>> under windows before rebooting or not.
<snip>
> Two vital pieces of info you left out -- like what brand/model (CM/dsl)
> modem and the name of your service provider/ISP.

Well, slap my thighs! i knew there was something i forgot to include. I'm
using a motorola surfboard 5100 and the ISP is telewest blueyonder.

> Sounds like your modem is cacheing client identifiers and Windows
> usually does it differently from Linux. There are several other
> posibilities but hard to guess what without the info.

It's a weird problem, it worked fine just half an hour ago when i rebooted
into linux. This time i waited a little after disabling the interface in
xp before rebooting, which i think would be consistent with allowing the
cache to empty before the reboot-am i right?

> You can use ethereal to inspect the dhcp packets being passed in a lease
> request by running it, then requesting a new lease. Obviously you can't
> use it at boot. It runs equally well on XP as Linux and capture files
> from one work in the other.

Will do. not sure what i'll be looking for in the captured dumps though
i'll try and figure it out.

> In any case, there is some item that is different in the XP request from
> the Linux request, and since unplugging the modem can "work" I suspect
> the modem is cacheing this info before it is ever sent upstream. No way
> to know without spec sheets/technical manuals or sniffing the wire.
>
> You might also look here for guidance if it is a provider quirk:
> http://www.dslreports.com/
>
> Here is an explanation of client-id differences. Note that some ISPs
> will not give out a new lease when quickly changing them -- like
> re-booting. Some just give out different IPs.
> http://homepage.ntlworld.com/robin.d...html#dhcpmulti

I thought the lease was for the IP?
Usually my IP doesn't change at reboot. One other thing, if the
problem is due to the different requests used then windows should have
trouble at boot time too, right? Windows has no trouble with enabling the
network interface, which suggests to me that there is a software method
for "resetting" the modem. I guess i'll find that out using ethereal.

Cheers for the info.

Kind Regards.

aq wrote:
> On Wed, 12 Jan 2005 20:44:05 -0800, prg wrote:
>
>
> > aq wrote:
> <snip>
> > Two vital pieces of info you left out -- like what brand/model
(CM/dsl)
> > modem and the name of your service provider/ISP.
>
> Well, slap my thighs! i knew there was something i forgot to include.
I'm
> using a motorola surfboard 5100 and the ISP is telewest blueyonder.
>
> > Sounds like your modem is cacheing client identifiers and Windows
> > usually does it differently from Linux. There are several other
> > posibilities but hard to guess what without the info.
>
> It's a weird problem, it worked fine just half an hour ago when i
rebooted
> into linux. This time i waited a little after disabling the interface
in
> xp before rebooting, which i think would be consistent with allowing
the
> cache to empty before the reboot-am i right?

I too have an SB5100 and before that an SB????? that acted as you
describe. Turned out it was the way the ISP was _using_
client-identifiers sent from my box.

Win always pre-pends 0x01 to the MAC address while Linux just sends the
MAC address untouched. To the dhcp server they "look" not quite the
same and it hiccups giving a new lease -- just how and for how long
depends on the ISP's config.

Mine eventually dissappeared -- mostly because I use Windows so _very_
little these days -- but also due to reconfiguration at the ISP's end.

Depending on how often you re-boot from one to the other (and if
Windows seems to "hold" its lease more tenaciously) one trick is to
release your lease before exiting Windows. Let's see, for XP that's
.... uhhh...
type ipconfig /release in the Command Prompt window and press Enter.

Remembering to do it is the hard part ;-)

> > You can use ethereal to inspect the dhcp packets being passed in a
lease
> > request by running it, then requesting a new lease. Obviously you
can't
> > use it at boot. It runs equally well on XP as Linux and capture
files
> > from one work in the other.
>
> Will do. not sure what i'll be looking for in the captured dumps
though
> i'll try and figure it out.

Can be fun and instructive to see how packets work, but probably
overkill with your added symptoms.

> > In any case, there is some item that is different in the XP request
from
> > the Linux request, and since unplugging the modem can "work" I
suspect
> > the modem is cacheing this info before it is ever sent upstream.
No way
> > to know without spec sheets/technical manuals or sniffing the wire.

This is BS in this case. The SB doesn't do this -- though there are
some that do. This is all a config issue at the head end, ie., your
ISP.

> > You might also look here for guidance if it is a provider quirk:
> > http://www.dslreports.com/
> >
> > Here is an explanation of client-id differences. Note that some
ISPs
> > will not give out a new lease when quickly changing them -- like
> > re-booting. Some just give out different IPs.
> >
http://homepage.ntlworld.com/robin.d...html#dhcpmulti
>
> I thought the lease was for the IP?

The lease _gives_ you an IP but it must be matched to the "proper"
owner and that usually means MAC address -- the supposedly globably
unique number burned into the nic by the maker. One nic, one
client-id, one IP address. Linux comes along with same nic (MAC), just
slightly different client-id, and server scratches its cpu wondering
what's the deal. This _is_ the technical explanation.

> Usually my IP doesn't change at reboot.

Several explanations for this behavior -- all out of your control.

> One other thing, if the
> problem is due to the different requests used then windows should
have
> trouble at boot time too, right?

This is the part that most depends on the ISP's setup. Some are very
Windows centric, and some just lean heavily in that direction. Real
mean ones, like Verizon in NY, insist on a client-id like
0x01:00:xx:xx:xx:xx:xx:xx:xx or they won't let you _out_ of their
private network onto the internet. Duh...

The ones that lean heavily in Windows direction will accept a "normal"
client-id but have to do some juggling to release the one your Win
client-id used.

> Windows has no trouble with enabling the
> network interface, which suggests to me that there is a software
method
> for "resetting" the modem. I guess i'll find that out using ethereal.

To get at the modem software, just point your web browser here:
http://192.168.100.1/startup.html
Click on Configuration. Reset Cable Modem is at bottom of page.

It's more reliable just to let go of the lease in Windows before
rebooting.

Do note that the last link I gave you has some specific pointers re:
BlueYonder. It's the best one-stop CM how-to and troubleshooting site
I've found.

regards and have fun,
prg
email above disabled

On Thu, 13 Jan 2005 20:04:52 -0800, rdgentry1 wrote:

<snip>
> I too have an SB5100 and before that an SB????? that acted as you
> describe. Turned out it was the way the ISP was _using_
> client-identifiers sent from my box.
>
> Win always pre-pends 0x01 to the MAC address while Linux just sends the
> MAC address untouched. To the dhcp server they "look" not quite the
> same and it hiccups giving a new lease -- just how and for how long
> depends on the ISP's config.
>
> Mine eventually dissappeared -- mostly because I use Windows so _very_
> little these days -- but also due to reconfiguration at the ISP's end.

Yea, i never used to have any problems-then we got some pretty cool games
for windows and i had no luck with cedega/wine so rebooting was necessary.

> Depending on how often you re-boot from one to the other (and if
> Windows seems to "hold" its lease more tenaciously) one trick is to
> release your lease before exiting Windows. Let's see, for XP that's
> ... uhhh...
> type ipconfig /release in the Command Prompt window and press Enter.
>
> Remembering to do it is the hard part ;-)

Damn, can't i write a shutdown script? One of the myriad of reasons I
really dislike windoze... And i just know that no matter how many
post-it's i put on the monitor, my mate won't remember...

<snip>
> This is BS in this case. The SB doesn't do this -- though there are
> some that do. This is all a config issue at the head end, ie., your
> ISP.
>
>> > You might also look here for guidance if it is a provider quirk:
>> > http://www.dslreports.com/
>> >
>> > Here is an explanation of client-id differences. Note that some
> ISPs
>> > will not give out a new lease when quickly changing them -- like
>> > re-booting. Some just give out different IPs.
>> >
> http://homepage.ntlworld.com/robin.d...html#dhcpmulti
>>
>> I thought the lease was for the IP?
>
> The lease _gives_ you an IP but it must be matched to the "proper"
> owner and that usually means MAC address -- the supposedly globably
> unique number burned into the nic by the maker. One nic, one
> client-id, one IP address. Linux comes along with same nic (MAC), just
> slightly different client-id, and server scratches its cpu wondering
> what's the deal. This _is_ the technical explanation.
>
>> Usually my IP doesn't change at reboot.
>
> Several explanations for this behavior -- all out of your control.

Not something i was particularly bothered about either, an IP is an IP, is
an IP. The way i look at it...

<snip>
> This is the part that most depends on the ISP's setup. Some are very
> Windows centric, and some just lean heavily in that direction. Real
> mean ones, like Verizon in NY, insist on a client-id like
> 0x01:00:xx:xx:xx:xx:xx:xx:xx or they won't let you _out_ of their
> private network onto the internet. Duh...

Isn't that like, discrimination or something?

<snip>
> To get at the modem software, just point your web browser here:
> http://192.168.100.1/startup.html
> Click on Configuration. Reset Cable Modem is at bottom of page.

Great stuff, but how would i do that from a command line? Is it even
possible?

> It's more reliable just to let go of the lease in Windows before
> rebooting.

Ideally, windows wouldn't add the stupid 0x01... Pretty off topic, but any
idea why it does this?

> Do note that the last link I gave you has some specific pointers re:
> BlueYonder. It's the best one-stop CM how-to and troubleshooting site
> I've found.
>
> regards and have fun,
> prg
> email above disabled

Cheers for the help-the links you gave me show something about modifying
the client address the dhclient sends, sounds promising.

Kind Regards.

aq wrote:
> On Thu, 13 Jan 2005 20:04:52 -0800, rdgentry1 wrote:
>
> <snip>
> >
> > Win always pre-pends 0x01 to the MAC address while Linux just sends
the
> > MAC address untouched. To the dhcp server they "look" not quite
the
> > same and it hiccups giving a new lease -- just how and for how long
> > depends on the ISP's config.
> >
> > Mine eventually dissappeared -- mostly because I use Windows so
_very_
> > little these days -- but also due to reconfiguration at the ISP's
end.
>
> Yea, i never used to have any problems-then we got some pretty cool
games
> for windows and i had no luck with cedega/wine so rebooting was
necessary.
>
> > Depending on how often you re-boot from one to the other (and if
> > Windows seems to "hold" its lease more tenaciously) one trick is to
> > release your lease before exiting Windows. Let's see, for XP
that's
> > ... uhhh...
> > type ipconfig /release in the Command Prompt window and press
Enter.
> >
> > Remembering to do it is the hard part ;-)
>
> Damn, can't i write a shutdown script? One of the myriad of reasons I
> really dislike windoze... And i just know that no matter how many
> post-it's i put on the monitor, my mate won't remember...

Possible -- even probable -- solution at end ;-)

> <snip>
>>
> >> > Here is an explanation of client-id differences. Note that some
> > ISPs
> >> > will not give out a new lease when quickly changing them -- like
> >> > re-booting. Some just give out different IPs.
> >> >
> >
http://homepage.ntlworld.com/robin.d...html#dhcpmulti
> >>
> <snip>
> > This is the part that most depends on the ISP's setup. Some are
very
> > Windows centric, and some just lean heavily in that direction.
Real
> > mean ones, like Verizon in NY, insist on a client-id like
> > 0x01:00:xx:xx:xx:xx:xx:xx:xx or they won't let you _out_ of their
> > private network onto the internet. Duh...
>
> Isn't that like, discrimination or something?
>
> <snip>
> > To get at the modem software, just point your web browser here:
> > http://192.168.100.1/startup.html
> > Click on Configuration. Reset Cable Modem is at bottom of page.
>
> Great stuff, but how would i do that from a command line? Is it even
> possible?
>
> > It's more reliable just to let go of the lease in Windows before
> > rebooting.
>
> Ideally, windows wouldn't add the stupid 0x01... Pretty off topic,
but any
> idea why it does this?
Typical MS approach to established behavior and standards -- adopt it
and "extend" it. "Why, Sonny, it ain't 'real' software without the
Windows stamp on it, now is it?" Ie., do it our way or suffer!


Sounds like you're ready for a more permanent solution.

What follows is a "to the best of my knowledge" remedy. There is
always a chance that I've misinterpreted the symptoms, but they do
sound familiar.

The trick -- like the suggestion in the CM link -- is to make Linux
look like the XP machine when it is requesting an IP at boot.
Fortunately, Linux provides a way to send an "arbitray" ID to the dhcpd
server. Unfortunately, RH/Fedora do it in a way that is relatively
undocumented -- you have to look at the ifup script to see what's going
on.

For fun -- probably not profit -- in an X terminal you can $ man
dhcp-options and $ man dhclient.conf to see some of the goodies
available. We're interested in dhcp-client-identifier.

I have no reason to believe XP has changed Windows behavior with SP2,
so I'll assume the old way remains the same.

We need the MAC address of the nic connected to the CM. In XP, I
believe, that would be ipconfig /all (displayed as Physical Address).
In Linux it is /sbin/ifconfig ethX (0,1,2, etc.).

We know XP will prepend a 1 or 01 to the MAC address so we need to:

send dhcp-client-identifier 1:MY:MA:CAD:RE:SS;
or
send dhcp-client-identifier 01:MY:MA:CAD:RE:SS;
I would try just adding the 1 to start with then try 01 if necessary.

Question is, "Where does this neato trick go?" This is the RH/Fedora
mystery question. There is no real dhclient.conf on these distros.
Instead we need to write this entry to:
/etc/dhclient-eth0.conf (or /etc/dhclient-eth1.conf for eth1, etc).
The sneaks, they give each nic its own conf file ;-)

There is a good chance that this file is _not_ on your system, so you
will need to create it. It is a plain ascii file, eg., zzz.txt. You
need to create it as root and give it these permissions: rw-r--r--
(read/write for user root, read only for group root, read only for
others).

Now when you reboot into Linux it should look like XP just wanting its
IP again. Same when you reboot into XP, obviously. Do make a note of
this file and why you did it in case any future changes (like removing
XP from the machine require you to get rid of it. Most likely you
could just empty it and leave the 0 byte file in place -- never know
when you might need it again.

If this doesn't work, then you'll need to sniff the wire and see how XP
is identifying itself to the dhcp server.
hth,
prg
email above disabled

On Fri, 14 Jan 2005 18:48:44 -0800, prg wrote:
<snip>
> Typical MS approach to established behavior and standards -- adopt it
> and "extend" it. "Why, Sonny, it ain't 'real' software without the
> Windows stamp on it, now is it?" Ie., do it our way or suffer!

LOL!

> Sounds like you're ready for a more permanent solution.

Yessir!

<snip>
> The trick -- like the suggestion in the CM link -- is to make Linux
> look like the XP machine when it is requesting an IP at boot.
> Fortunately, Linux provides a way to send an "arbitray" ID to the dhcpd
> server. Unfortunately, RH/Fedora do it in a way that is relatively
> undocumented -- you have to look at the ifup script to see what's going
> on.

Yea, i had a look at the man pages for dhclient and the seperate one for
dhclient.conf. Fedora has a sample config file, but it is a _scary_
thing to even look at!

> For fun -- probably not profit -- in an X terminal you can $ man
> dhcp-options and $ man dhclient.conf to see some of the goodies
> available. We're interested in dhcp-client-identifier.

Spotted it in the sample. I'm hoping _that_ one line is the only necessary
one, so far, so good.

<snip>
> We know XP will prepend a 1 or 01 to the MAC address so we need to:
>
> send dhcp-client-identifier 1:MY:MA:CAD:RE:SS; or send
> dhcp-client-identifier 01:MY:MA:CAD:RE:SS; I would try just adding the
> 1 to start with then try 01 if necessary.
>
> Question is, "Where does this neato trick go?" This is the RH/Fedora
> mystery question. There is no real dhclient.conf on these distros.
> Instead we need to write this entry to: /etc/dhclient-eth0.conf (or
> /etc/dhclient-eth1.conf for eth1, etc). The sneaks, they give each nic
> its own conf file ;-)

Ahh, the penny drops! :-)

I had my box setup to boot automagically at night, start the edonkey
client and switch off in the morning. Can you imagine my frustration when
it had done nothing, all because my mate wanted to play a game sometime in
the afternoon?

Thank you so much for the info. Only to test it now :-)