Thinstation strange DHCP behavior

classic Classic list List threaded Threaded
4 messages Options
Reply | Threaded
Open this post in threaded view
|

Thinstation strange DHCP behavior

Eli-54
Hi,
Im trying to debug some DHCP issues that we are having, and am running
into very strange behavior by our thinstation clients.

The clients boot off of PXE, so they request from DHCP server a IP and
are assigned one.
As soon as they finish downloading the image from TFTP they request a
new IP address.
Can anyone shed some light on this strange behavior?

Here are some logs from the DHCP server.
As you see, initially its assigned 192.168.1.162, and uses that address
to download TFTP.
It then does a DISCOVER again and is assigned 192.168.1.198

Jun 21 19:57:54 dhcp1 dhcpd: DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:55 dhcp1 dhcpd: DHCPOFFER on 192.168.1.162 to
80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:58 dhcp1 dhcpd: DHCPREQUEST for 192.168.1.162
(192.168.1.31) from 80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:58 dhcp1 dhcpd: DHCPACK on 192.168.1.162 to
80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:58 dhcp1 in.tftpd[2955]: tftp: client does not accept options
Jun 21 19:57:58 dhcp1 in.tftpd[2956]: Client 192.168.1.162 finished
pxelinux.0
Jun 21 19:57:58 dhcp1 in.tftpd[2967]: Client 192.168.1.162 finished
pxelinux.cfg/default
Jun 21 19:57:58 dhcp1 in.tftpd[2968]: Client 192.168.1.162 finished
product.txt
Jun 21 19:57:59 dhcp1 in.tftpd[2969]: Client 192.168.1.162 finished vmlinuz
Jun 21 19:58:19 dhcp1 in.tftpd[2970]: Client 192.168.1.162 finished initrd
Jun 21 19:58:32 dhcp1 dhcpd: DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0
Jun 21 19:58:33 dhcp1 dhcpd: DHCPOFFER on 192.168.1.198 to
80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0
Jun 21 19:58:33 dhcp1 dhcpd: DHCPREQUEST for 192.168.1.198
(192.168.1.31) from 80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0
Jun 21 19:58:33 dhcp1 dhcpd: DHCPACK on 192.168.1.198 to
80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0
Jun 21 19:58:33 dhcp1 in.tftpd[2977]: Client 192.168.1.198 finished
ts5.2/thinstation.conf.network


Thanks,
Eli

------------------------------------------------------------------------------
Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San
Francisco, CA to explore cutting-edge tech and listen to tech luminaries
present their vision of the future. This family event has something for
everyone, including kids. Get more information and register today.
http://sdm.link/attshape
_______________________________________________
Thinstation-general mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/thinstation-general
Reply | Threaded
Open this post in threaded view
|

Re: Thinstation strange DHCP behavior

David Pollard
Hi Eli,
It seems normal that the client would make two requests for an IP address.
The first time when it boots from the network card and downloads the image
from the tftp server.
The second when it boots from the downloaded image I'd expect that it would
need to ask again.  (This is my assumption I have never investigated this)
I can see both requests use the same MAC address so I'd also expect the DHCP
server to offer the same IP address again as this is normal DHCP
functionality.

If you restart the workstation again does it receive two different IP
addresses or does it use the same two again?

>From the log information From the end of one DHCP request to the start of
the next is only 13ms
So I don't think anything much is happening between these two requests.

Jun 21 19:58:19 dhcp1 in.tftpd[2970]: Client 192.168.1.162 finished initrd
Jun 21 19:58:32 dhcp1 dhcpd: DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0

A quick google turned up something called a DHCP Client ID that I have not
herd of before.
I don't know if it could be generating different Client ID's and there for
getting a different IP address each time.

Not much help but maybe this will give you something else to think about.
David


-----Original Message-----
From: Eli [mailto:[hidden email]]
Sent: Wednesday, 22 June 2016 10:56 PM
To: [hidden email]
Subject: [Thinstation-general] Thinstation strange DHCP behavior

Hi,
Im trying to debug some DHCP issues that we are having, and am running into
very strange behavior by our thinstation clients.

The clients boot off of PXE, so they request from DHCP server a IP and are
assigned one.
As soon as they finish downloading the image from TFTP they request a new IP
address.
Can anyone shed some light on this strange behavior?

Here are some logs from the DHCP server.
As you see, initially its assigned 192.168.1.162, and uses that address to
download TFTP.
It then does a DISCOVER again and is assigned 192.168.1.198

Jun 21 19:57:54 dhcp1 dhcpd: DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:55 dhcp1 dhcpd: DHCPOFFER on 192.168.1.162 to
80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:58 dhcp1 dhcpd: DHCPREQUEST for 192.168.1.162
(192.168.1.31) from 80:ee:73:5b:1c:d9 via eth0 Jun 21 19:57:58 dhcp1 dhcpd:
DHCPACK on 192.168.1.162 to
80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:58 dhcp1 in.tftpd[2955]: tftp: client does not accept options
Jun 21 19:57:58 dhcp1 in.tftpd[2956]: Client 192.168.1.162 finished
pxelinux.0
Jun 21 19:57:58 dhcp1 in.tftpd[2967]: Client 192.168.1.162 finished
pxelinux.cfg/default Jun 21 19:57:58 dhcp1 in.tftpd[2968]: Client
192.168.1.162 finished product.txt Jun 21 19:57:59 dhcp1 in.tftpd[2969]:
Client 192.168.1.162 finished vmlinuz Jun 21 19:58:19 dhcp1 in.tftpd[2970]:
Client 192.168.1.162 finished initrd Jun 21 19:58:32 dhcp1 dhcpd:
DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0 Jun 21 19:58:33 dhcp1 dhcpd:
DHCPOFFER on 192.168.1.198 to
80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0 Jun 21 19:58:33 dhcp1 dhcpd:
DHCPREQUEST for 192.168.1.198
(192.168.1.31) from 80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0 Jun 21
19:58:33 dhcp1 dhcpd: DHCPACK on 192.168.1.198 to
80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0 Jun 21 19:58:33 dhcp1
in.tftpd[2977]: Client 192.168.1.198 finished ts5.2/thinstation.conf.network


Thanks,
Eli

----------------------------------------------------------------------------
--
Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San
Francisco, CA to explore cutting-edge tech and listen to tech luminaries
present their vision of the future. This family event has something for
everyone, including kids. Get more information and register today.
http://sdm.link/attshape
_______________________________________________
Thinstation-general mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/thinstation-general


------------------------------------------------------------------------------
Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San
Francisco, CA to explore cutting-edge tech and listen to tech luminaries
present their vision of the future. This family event has something for
everyone, including kids. Get more information and register today.
http://sdm.link/attshape
_______________________________________________
Thinstation-general mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/thinstation-general
Reply | Threaded
Open this post in threaded view
|

Re: Thinstation strange DHCP behavior

Guilherme Scaglia

Eli,

Just in case, did you check if there is more than one DHCP server on your network?

The thinclient realy do two discovery requests, one during PXE and other during Thinstation boot, and that cannot be changed. I've seen the behavior you describe when there is more than one DHCP on my network, and when that is the case the thinclient consistently gets an address from one server during PXE and from other after booting.

Best Regards,

Guilherme Costa Scaglia


On 22/06/2016 22:09, David Pollard wrote:
Hi Eli,
It seems normal that the client would make two requests for an IP address.
The first time when it boots from the network card and downloads the image
from the tftp server.
The second when it boots from the downloaded image I'd expect that it would
need to ask again.  (This is my assumption I have never investigated this)
I can see both requests use the same MAC address so I'd also expect the DHCP
server to offer the same IP address again as this is normal DHCP
functionality.

If you restart the workstation again does it receive two different IP
addresses or does it use the same two again?

>From the log information From the end of one DHCP request to the start of
the next is only 13ms
So I don't think anything much is happening between these two requests.

Jun 21 19:58:19 dhcp1 in.tftpd[2970]: Client 192.168.1.162 finished initrd 
Jun 21 19:58:32 dhcp1 dhcpd: DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0

A quick google turned up something called a DHCP Client ID that I have not
herd of before.
I don't know if it could be generating different Client ID's and there for
getting a different IP address each time.

Not much help but maybe this will give you something else to think about.
David


-----Original Message-----
From: Eli [[hidden email]] 
Sent: Wednesday, 22 June 2016 10:56 PM
To: [hidden email]
Subject: [Thinstation-general] Thinstation strange DHCP behavior

Hi,
Im trying to debug some DHCP issues that we are having, and am running into
very strange behavior by our thinstation clients.

The clients boot off of PXE, so they request from DHCP server a IP and are
assigned one.
As soon as they finish downloading the image from TFTP they request a new IP
address.
Can anyone shed some light on this strange behavior?

Here are some logs from the DHCP server.
As you see, initially its assigned 192.168.1.162, and uses that address to
download TFTP.
It then does a DISCOVER again and is assigned 192.168.1.198

Jun 21 19:57:54 dhcp1 dhcpd: DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:55 dhcp1 dhcpd: DHCPOFFER on 192.168.1.162 to
80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:58 dhcp1 dhcpd: DHCPREQUEST for 192.168.1.162
(192.168.1.31) from 80:ee:73:5b:1c:d9 via eth0 Jun 21 19:57:58 dhcp1 dhcpd:
DHCPACK on 192.168.1.162 to
80:ee:73:5b:1c:d9 via eth0
Jun 21 19:57:58 dhcp1 in.tftpd[2955]: tftp: client does not accept options
Jun 21 19:57:58 dhcp1 in.tftpd[2956]: Client 192.168.1.162 finished
pxelinux.0
Jun 21 19:57:58 dhcp1 in.tftpd[2967]: Client 192.168.1.162 finished
pxelinux.cfg/default Jun 21 19:57:58 dhcp1 in.tftpd[2968]: Client
192.168.1.162 finished product.txt Jun 21 19:57:59 dhcp1 in.tftpd[2969]:
Client 192.168.1.162 finished vmlinuz Jun 21 19:58:19 dhcp1 in.tftpd[2970]:
Client 192.168.1.162 finished initrd Jun 21 19:58:32 dhcp1 dhcpd:
DHCPDISCOVER from 80:ee:73:5b:1c:d9 via eth0 Jun 21 19:58:33 dhcp1 dhcpd:
DHCPOFFER on 192.168.1.198 to
80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0 Jun 21 19:58:33 dhcp1 dhcpd:
DHCPREQUEST for 192.168.1.198
(192.168.1.31) from 80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0 Jun 21
19:58:33 dhcp1 dhcpd: DHCPACK on 192.168.1.198 to
80:ee:73:5b:1c:d9 (ts_80ee735b1cd9) via eth0 Jun 21 19:58:33 dhcp1
in.tftpd[2977]: Client 192.168.1.198 finished ts5.2/thinstation.conf.network


Thanks,
Eli

----------------------------------------------------------------------------
--
Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San
Francisco, CA to explore cutting-edge tech and listen to tech luminaries
present their vision of the future. This family event has something for
everyone, including kids. Get more information and register today.
http://sdm.link/attshape
_______________________________________________
Thinstation-general mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/thinstation-general


------------------------------------------------------------------------------
Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San
Francisco, CA to explore cutting-edge tech and listen to tech luminaries
present their vision of the future. This family event has something for
everyone, including kids. Get more information and register today.
http://sdm.link/attshape
_______________________________________________
Thinstation-general mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/thinstation-general


------------------------------------------------------------------------------
Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San
Francisco, CA to explore cutting-edge tech and listen to tech luminaries
present their vision of the future. This family event has something for
everyone, including kids. Get more information and register today.
http://sdm.link/attshape
_______________________________________________
Thinstation-general mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/thinstation-general
Reply | Threaded
Open this post in threaded view
|

Re: Thinstation strange DHCP behavior

frank
In reply to this post by Eli-54
Eli,
which version of thinstation do you use?

Cheers Frank