FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Ubuntu > Edubuntu User

 
 
LinkBack Thread Tools
 
Old 12-14-2008, 09:42 PM
Gavin McCullagh
 
Default DHCP server sometimes not found

Hi,

On Sun, 14 Dec 2008, Sergio Dicandia wrote:

> I'm finishing our new computer room with 12 thin clients and a 8.041
> Edubuntu server. Everything seemed fine on the first clients I tested,
> but I just found I can start no more than 4 or 5 at the same time.

> The other ones just wait for a DHCP to give them a valid IP address, and there's no way to obtain it.
> I checked cabling and switch, but it's just a matter of who come first: the first 4 (or 5) clients just get their IP, the other ones don't.
> Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC addresses to assign fixed IPs, and they work fine for the first clients starting.
>
> Looks like somebody had the same problem, while everything worked fine in 7.10 with LTSP 4.2:
> http://209.85.129.132/search?q=cache:Jj3ycleLzasJ:sudan.ubuntuforums.com/showthread.php%3Ft%3D830748+edubuntu+dhcp+problem& hl=it&ct=clnk&cd=8&gl=it&client=firefox-a

Could you login to the server and run:

sudo tcpdump -n -i eth0 udp port 67 or port 68

(you might need to change eth0 to eth1 if that's your network interface
which faces the thin clients) then boot the clients in turn.

What you should see is the thin clients making dhcp requests and dhcp
responses going back from the server. If the client requests don't get to
the server, that'll be clear. Whether the server replies should also be
clear. Once you know this, it'll be easier to tell where the problem is.

Gavin


--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-14-2008, 11:23 PM
Christopher Chan
 
Default DHCP server sometimes not found

Sergio Dicandia wrote:
> Hi,
>
> I'm finishing our new computer room with 12 thin clients and a 8.041
> Edubuntu server. Everything seemed fine on the first clients I tested,
> but I just found I can start no more than 4 or 5 at the same time.
> The other ones just wait for a DHCP to give them a valid IP address, and
> there's no way to obtain it.

Are those that get ip addresses and those that do not get ip addresses
the same machines each time round?

> I checked cabling and switch, but it's just a matter of who come first:
> the first 4 (or 5) clients just get their IP, the other ones don't.
> Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC addresses
> to assign fixed IPs, and they work fine for the first clients starting.

Are you using Cisco switches?

--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-15-2008, 03:02 AM
"Rippl, Steve"
 
Default DHCP server sometimes not found

We found exactly the same thing. We took dhcp off the ltsp server and
put it on a separate box (a low power P4) and suddenly were able to boot
30 clients at the same time (with ltsp5).

It seems that ltsp5 hammers the dhcp server (at least from Ubuntu,
that's all we've tested so far), I think if you watch the logs you find
the clients querying the dhcp server over and over again. We figured
that as the box got busy serving up the tftp kernels the dhcp would
start to fail/timeout.

For this and other reasons (Active Directory authentication hammering
the server too, general slowness) we went back to ltsp4 (on Debian) and
things are working much better there in general, it's much faster!

Steve Rippl
Woodland School District.

________________________________________
From: edubuntu-users-bounces@lists.ubuntu.com
[mailto:edubuntu-users-bounces@lists.ubuntu.com] On Behalf Of Sergio
Dicandia
Sent: Sunday, December 14, 2008 2:28 PM
To: edubuntu-users@lists.ubuntu.com
Subject: DHCP server sometimes not found

Hi,

I'm finishing our new computer room with 12 thin clients and a 8.041
Edubuntu server. Everything seemed fine on the first clients I tested,
but I just found I can start no more than 4 or 5 at the same time.
The other ones just wait for a DHCP to give them a valid IP address, and
there's no way to obtain it.
I checked cabling and switch, but it's just a matter of who come first:
the first 4 (or 5) clients just get their IP, the other ones don't.
Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC addresses
to assign fixed IPs, and they work fine for the first clients starting.

Looks like somebody had the same problem, while everything worked fine
in 7.10 with LTSP 4.2:
http://209.85.129.132/search?q=cache:Jj3ycleLzasJ:sudan.ubuntuforums.com
/showthread.php%3Ft%3D830748+edubuntu+dhcp+problem& hl=it&ct=clnk&cd=8&gl
=it&client=firefox-a

Any suggestion ?
It's the last obstacle to get our only computer room working ...

TIA,
Sergio


--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-15-2008, 11:44 AM
 
Default DHCP server sometimes not found

We found EXACTLY the same thing. We went back to CentOS and LTSP 4.2.
30 clients booted at the same time. The only problem then was with
sound and flash....


Ron

-------- Original Message --------
Subject: RE: DHCP server sometimes not found
From: "Rippl, Steve" <rippls@woodlandschools.org>
Date: Sun, December 14, 2008 10:02 pm
To: "Sergio Dicandia" <sdicandia@yahoo.com>,
<edubuntu-users@lists.ubuntu.com>

We found exactly the same thing. We took dhcp off the ltsp server and
put it on a separate box (a low power P4) and suddenly were able to boot
30 clients at the same time (with ltsp5).

It seems that ltsp5 hammers the dhcp server (at least from Ubuntu,
that's all we've tested so far), I think if you watch the logs you find
the clients querying the dhcp server over and over again. We figured
that as the box got busy serving up the tftp kernels the dhcp would
start to fail/timeout.

For this and other reasons (Active Directory authentication hammering
the server too, general slowness) we went back to ltsp4 (on Debian) and
things are working much better there in general, it's much faster!

Steve Rippl
Woodland School District.

________________________________________
From: edubuntu-users-bounces@lists.ubuntu.com
[mailto:edubuntu-users-bounces@lists.ubuntu.com] On Behalf Of Sergio
Dicandia
Sent: Sunday, December 14, 2008 2:28 PM
To: edubuntu-users@lists.ubuntu.com
Subject: DHCP server sometimes not found

Hi,

I'm finishing our new computer room with 12 thin clients and a 8.041
Edubuntu server. Everything seemed fine on the first clients I tested,
but I just found I can start no more than 4 or 5 at the same time.
The other ones just wait for a DHCP to give them a valid IP address, and
there's no way to obtain it.
I checked cabling and switch, but it's just a matter of who come first:
the first 4 (or 5) clients just get their IP, the other ones don't.
Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC addresses
to assign fixed IPs, and they work fine for the first clients starting.

Looks like somebody had the same problem, while everything worked fine
in 7.10 with LTSP 4.2:
http://209.85.129.132/search?q=cache:Jj3ycleLzasJ:sudan.ubuntuforums.com
/showthread.php%3Ft%3D830748+edubuntu+dhcp+problem& hl=it&ct=clnk&cd=8&gl
=it&client=firefox-a

Any suggestion ?
It's the last obstacle to get our only computer room working ...

TIA,
Sergio


--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at:
https://lists.ubuntu.com/mailman/listinfo/edubuntu-users




--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-15-2008, 07:38 PM
Thierry Munoz
 
Default DHCP server sometimes not found

I rewrite the answer I made this afternoon to Sergio because I made a
mistake to reply (I forgot to send to this list)...



Hi,

I have the same problem with an Eee Box B202 as thin client. I don't
know why : this occurs often but randomly.

I have to restart the DHCP server in order that the Eee Box boot
correctly.

I had to type in my server :

sudo /etc/init.d/dhcp3-server start

or

sudo invoke-rc.d
dhcp3-server restart


Regards,



Thierry



Sergio Dicandia a écrit*:



Hi,



I'm finishing our new computer room with 12 thin clients and a 8.041
Edubuntu server. Everything seemed fine on the first clients I tested,
but I just found I can start no more than 4 or 5 at the same time.

The other ones just wait for a DHCP to give them a valid IP address,
and there's no way to obtain it.

I checked cabling and switch, but it's just a matter of who come first:
the first 4 (or 5) clients just get their IP, the other ones don't.

Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC
addresses to assign fixed IPs, and they work fine for the first clients
starting.



Looks like somebody had the same problem, while everything worked fine
in 7.10 with LTSP 4.2:

http://209.85.129.132/search?q=cache:Jj3ycleLzasJ:sudan.ubuntuforums.com/showthread.php%3Ft%3D830748+edubuntu+dhcp+problem& hl=it&ct=clnk&cd=8&gl=it&client=firefox-a



Any suggestion ?

It's the last obstacle to get our only computer room working ...



TIA,

Sergio









--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-17-2008, 08:12 PM
Sergio Dicandia
 
Default DHCP server sometimes not found

Thanks a lot, Steve

Has anybody tried this with Intrepid ? Maybe they fixed it in the new release ...

From: "Rippl, Steve" <rippls@woodlandschools.org>
To: Sergio Dicandia <sdicandia@yahoo.com>; edubuntu-users@lists.ubuntu.com
Sent: Monday, December 15, 2008 5:02:54 AM
Subject: RE: DHCP server sometimes not found


We found exactly the same thing.* We took dhcp off the ltsp server and
put it on a separate box (a low power P4) and suddenly were able to boot
30 clients at the same time (with ltsp5).

It seems that ltsp5 hammers the dhcp server (at least from Ubuntu,
that's all we've tested so far), I think if you watch the logs you find
the clients querying the dhcp server over and over again.* We figured
that as the box got busy serving up the tftp kernels the dhcp would
start to fail/timeout.

For this and other reasons (Active Directory authentication hammering
the server too, general slowness) we went back to ltsp4 (on Debian) and
things are working much better there in general, it's much faster!

Steve Rippl
Woodland School District.

________________________________________
From: edubuntu-users-bounces@lists.ubuntu.com
[mailto:edubuntu-users-bounces@lists.ubuntu.com] On Behalf Of Sergio
Dicandia
Sent: Sunday, December 14, 2008 2:28 PM
To: edubuntu-users@lists.ubuntu.com
Subject: DHCP server sometimes not found

Hi,

I'm finishing our new computer room with 12 thin clients and a 8.041
Edubuntu server. Everything seemed fine on the first clients I tested,
but I just found I can start no more than 4 or 5 at the same time.
The other ones just wait for a DHCP to give them a valid IP address, and
there's no way to obtain it.
I checked cabling and switch, but it's just a matter of who come first:
the first 4 (or 5)
clients just get their IP, the other ones don't.
Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC addresses
to assign fixed IPs, and they work fine for the first clients starting.

Looks like somebody had the same problem, while everything worked fine
in 7.10 with LTSP 4.2:
http://209.85.129.132/search?q=cache:Jj3ycleLzasJ:sudan.ubuntuforums.com
/showthread.php%3Ft%3D830748+edubuntu+dhcp+problem& hl=it&ct=clnk&cd=8&gl
=it&client=firefox-a

Any suggestion ?
It's the last obstacle to get our only computer room working ...

TIA,
Sergio




--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-17-2008, 08:12 PM
Sergio Dicandia
 
Default DHCP server sometimes not found

Thanks a lot, Steve



Has anybody tried this with Intrepid ?
Maybe they fixed it in the new release ...

Thanks,
Sergio

From: "Rippl, Steve" <rippls@woodlandschools.org>
To: Sergio Dicandia <sdicandia@yahoo.com>; edubuntu-users@lists.ubuntu.com
Sent: Monday, December 15, 2008 5:02:54 AM
Subject: RE: DHCP server sometimes not found


We found exactly the same thing.* We took dhcp off the ltsp server and
put it on a separate box (a low power P4) and suddenly were able to boot
30 clients at the same time (with ltsp5).

It seems that ltsp5 hammers the dhcp server (at least from Ubuntu,
that's all we've tested so far), I think if you watch the logs you find
the clients querying the dhcp server over and over again.* We figured
that as the box got busy serving up the tftp kernels the dhcp would
start to fail/timeout.

For this and other reasons (Active Directory authentication hammering
the server too, general slowness) we went back to ltsp4 (on Debian) and
things are working much better there in general, it's much faster!

Steve Rippl
Woodland School District.

________________________________________
From: edubuntu-users-bounces@lists.ubuntu.com
[mailto:edubuntu-users-bounces@lists.ubuntu.com] On Behalf Of Sergio
Dicandia
Sent: Sunday, December 14, 2008 2:28 PM
To: edubuntu-users@lists.ubuntu.com
Subject: DHCP server sometimes not found

Hi,

I'm finishing our new computer room with 12 thin clients and a 8.041
Edubuntu server. Everything seemed fine on the first clients I tested,
but I just found I can start no more than 4 or 5 at the same time.
The other ones just wait for a DHCP to give them a valid IP address, and
there's no way to obtain it.
I checked cabling and switch, but it's just a matter of who come first:
the first 4 (or 5)
clients just get their IP, the other ones don't.
Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC addresses
to assign fixed IPs, and they work fine for the first clients starting.

Looks like somebody had the same problem, while everything worked fine
in 7.10 with LTSP 4.2:
http://209.85.129.132/search?q=cache:Jj3ycleLzasJ:sudan.ubuntuforums.com
/showthread.php%3Ft%3D830748+edubuntu+dhcp+problem& hl=it&ct=clnk&cd=8&gl
=it&client=firefox-a

Any suggestion ?
It's the last obstacle to get our only computer room working ...

TIA,
Sergio




--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-17-2008, 09:17 PM
Gavin McCullagh
 
Default DHCP server sometimes not found

Hi,

On Wed, 17 Dec 2008, Sergio Dicandia wrote:

> Has anybody tried this with Intrepid ?
> Maybe they fixed it in the new release ...

Several of the LTSP developers read this list so if they know of this
problem and a fix to this, you may be sure they'll say.

In the meantime, we need to document this better for them.

Can you please do the tcpdump on the server so we can make sure of what's
going on (give us the tcpdump trace along with what roughly moments you
booted what machines/mac addresses). It sounds like this _might_ be a
nasty bug which several people have seen and if so, we need to know exactly
what happens. If there's a serious issue we need to reproduce it and pin
it down so the developers can fix it.

Gavin


--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 12-18-2008, 12:01 PM
Sergio Dicandia
 
Default DHCP server sometimes not found

Thanks Steve,
I'll try and get the dump needed to pinpoint the problema.
In the meantime, I could follow your suggestion to move DHCP to another box* (IPCop ?).
How did you do that ? What should I cange on my LTSP box ?

Thanks again,
Sergio

From: "Rippl, Steve" <rippls@woodlandschools.org>
To: Sergio Dicandia <sdicandia@yahoo.com>; edubuntu-users@lists.ubuntu.com
Sent: Monday, December 15, 2008 5:02:54
AM
Subject: RE: DHCP server sometimes not found


We found exactly the same thing.* We took dhcp off the ltsp server and
put it on a separate box (a low power P4) and suddenly were able to boot
30 clients at the same time (with ltsp5).

It seems that ltsp5 hammers the dhcp server (at least from Ubuntu,
that's all we've tested so far), I think if you watch the logs you find
the clients querying the dhcp server over and over again.* We figured
that as the box got busy serving up the tftp kernels the dhcp would
start to fail/timeout.

For this and other reasons (Active Directory authentication hammering
the server too, general slowness) we went back to ltsp4 (on Debian) and
things are working much better there in general, it's much faster!

Steve Rippl
Woodland School District.

________________________________________
From: edubuntu-users-bounces@lists.ubuntu.com
[mailto:edubuntu-users-bounces@lists.ubuntu.com] On Behalf Of Sergio
Dicandia
Sent: Sunday, December 14, 2008 2:28 PM
To: edubuntu-users@lists.ubuntu.com
Subject: DHCP server sometimes not found

Hi,

I'm finishing our new computer room with 12 thin clients and a 8.041
Edubuntu server. Everything seemed fine on the first clients I tested,
but I just found I can start no more than 4 or 5 at the same time.
The other ones just wait for a DHCP to give them a valid IP address, and
there's no way to obtain it.
I checked cabling and switch, but it's just a matter of who come first:
the first 4 (or 5)
clients just get their IP, the other ones don't.
Consider that in my /etc/ltsp/dhcpd.conf I put the correct MAC addresses
to assign fixed IPs, and they work fine for the first clients starting.

Looks like somebody had the same problem, while everything worked fine
in 7.10 with LTSP 4.2:
http://209.85.129.132/search?q=cache:Jj3ycleLzasJ:sudan.ubuntuforums.com
/showthread.php%3Ft%3D830748+edubuntu+dhcp+problem& hl=it&ct=clnk&cd=8&gl
=it&client=firefox-a

Any suggestion ?
It's the last obstacle to get our only computer room working ...

TIA,
Sergio




--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 
Old 01-21-2009, 07:57 PM
Sergio Dicandia
 
Default DHCP server sometimes not found

No luck with DHCP ... it still doesn't give more than 4 (or 5 at best) addresses and then it freezes ....
I did the tcpdump as suggested, you can find it attached ...

Now I'm thinking to replace the DHCP server, but I need something on the server itself, or on a device (the router, maybe) since I cannot ask the teacher to:
1- start a service machine (acting as a DHCP server)
2 - wait until it's up&running
3 - start the server
4 - start the TCs

Way too tricky for people used to switch on a general button and have all the PCs running (OK, WindowsME, but)
What about a router ? I also need to assign fixed IPs to specific MAC adddresses to be able to use iTalc ...

:-(* I'm very sad about this
....


--------------------------------------
Message: 5
Date: Wed, 17 Dec 2008 22:17:36 +0000
From: Gavin McCullagh <gmccullagh@gmail.com>
Subject: Re: DHCP server sometimes not found
To: edubuntu-users@lists.ubuntu.com
Message-ID: <20081217221736.GD12257@gmail.com>
Content-Type: text/plain; charset=us-ascii

Hi,

On Wed, 17 Dec 2008, Sergio Dicandia wrote:

> Has anybody tried this with Intrepid ?
> Maybe they fixed it in the new release ...

Several of the LTSP developers read this list so
if they know of this
problem and a fix to this, you may be sure they'll say.

In the meantime, we need to document this better for them.

Can you please do the tcpdump on the server so we can make sure of what's
going on (give us the tcpdump trace along with what roughly moments you
booted what machines/mac addresses).* It sounds like this _might_ be a
nasty bug which several people have seen and if so, we need to know exactly
what happens.* If there's a serious issue we need to reproduce it and pin
it down so the developers can fix it.

Gavin



--
edubuntu-users mailing list
edubuntu-users@lists.ubuntu.com
Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
 

Thread Tools




All times are GMT. The time now is 02:50 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright ©2007 - 2008, www.linux-archive.org