Round Robin RIS

J

Jon Pratt

Okay, so I've been looking through NGs for a while now to see if
anyone's figured this one out yet and so far I've come up empty
handed. I want to increase the available bandwidth for our RIS
clients. We currently run a cisco chassis switch which allows us to
have multiple Gb throughput to our servers and we're finding that for
RIS a single gigabit NIC just isn't cutting it (I work for a school
district and we often find ourselves imaging 200-500 machines
simultaneously). No matter what I do I cannot seem to get round robin
load balancing to work for RIS. I've tried using DHCP option 66 and
specified a multiple IP host name but the clients only go to one
IP/NIC(i've been unable to find PXE documentation granular enough to
find out who resolves the hostname i.e. the DHCP server or the PXE
client, although I suspect that it's the client but I'm not sure).
I've confirmed that round robin works and I even tried turning off DNS
caching on the DHCP server so that it wouldn't cache resolved IPs in
case it was the DHCP server that resolves the hostname first before
sending it to the PXE client. I've also tried running DHCP and RIS on
the same box with the same result i.e. it directs all clients to the
same IP/NIC for RIS (yes I authorized each IP). One thing that I did
discover is that I can easily change the IP/NIC that a client uses. If
I put only one host record in DNS for the RIS server, we'll call it
ris1.domain.com, clients will then use the IP/NIC associated with
ris1.domain.com. Interestingly when I add a new host record, we'll
call it ris2.domain.com, pointing to another IP/NIC, it will ignore it
and keep sending clients to the first address, but as soon as I delete
the ris1.domain.com record it immediately finds ris2.domain.com and
starts sending clients to that IP/NIC. My conclusion from this is
that DNS is in fact being queried but for some reason the ability to
use round robin is inactive?... Has anyone out there been able to get
RIS to use multiple NICs simultaneously? I'd also be interested in
any hardware solutions that might work. Thanks.

Note: I'm not having a problem getting RIS to work on a multihomed
machine as described in KB260521. I'm having a problem getting RIS to
take advantage of a multihomed system i.e. RIS through multiple NICs
simultaneously.
 
S

Steve Marfisi

Hi Jon -

although this may not specifically address your issue, it may help. We
(emBoot) have software called PXE Server Directory Service (PXESDS)
that can direct your PXE clients to a particular PXE server, by
NetBIOS name or by IP number. It does require our client piece boot
firmware, and can work within your present PXE environment. Please see
http://www.emboot.com/PDFgallery-PXESDS.htm for some documentation on
it, and http://www.emboot.com/PXESDS.swf for a brief flash
presentation.

Feel free to contact me regarding this or any other solutions
regarding your network boot environment.

Steve Marfisi
www.emboot.com
905.629.0200
 
J

Jon Pratt

Steve, perhaps I am not correctly understanding how your product works, but
as best I can tell it would have the same limitation in regard to load
balancing i.e. it would not be able to load balance RIS clients by
distributing them in a "round robin" fashion to multiple NICs of the same
RIS server. Please let me know if this is not the case as we would be very
interested in a product that could accomplish this. Thanks.
 

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