RIS Through Cisco

[KyleJ]

Scenario: Classroom Server is serving RIS for the student positions. The RIS server is configured and working correctly. Student position consist of two Gateway 9515s running 2003, two 9315s running XpPro, one Cisco 1841(12.4, serving DHCP), one gigabit switch. The configuration information is below;

RIS Server;

IP address: 192.168.164.2

Subnet Mk: 255.255.255.0

Default Rt: 192.168.164.1

DNS PRI: 192.168.191.11

DNS SEC: 192.168.191.12

Student POS (There are eight of them 10-80)

Router Addresses

Wan: 192.168.164.10 (classroom network)

Lan: 10.164.10.1 (student's network)

Router DHCP Info:

IP address: 10.164.10.20-10.164.10.254

Subnet Mk: 255.255.255.0

Default Rt: 10.164.10.1

DNS PRI: 10.164.10.10

DNS SEC: 192.168.191.11

Currently, to provide the student RIS we have to remove the student router from the loop. The student WAN cable gets plugged into the student switch. I need to somehow configure the cisco to supply the DHCP address but foward the boot request to the RIS server. I have tried "IP Helper Address" and "next-server", probably wrong. Has anyone gotten RIS to work through a router without using DHCP Relay? I know that this is more of a cisco issue, so if anyone knows a good cisco site to try that would also be helpful.

[Fencer128]

Hi,

I haven't had time to run through all your post as I'm quite busy at the moment, but it may be worth your while having a look at this:

http://www-w2k.cs.berkeley.edu/admin/docs/docs/dhcpris.txt

It could be of use to you if you have your clients and either the RIS and/or DHCP servers on different subnets.

Good luck,

Andy

[RogueSpear]

Is it in fact necessary to have your Cisco device acting as a DHCP server? I've never run across a situation like that before. In any case, it's to my understanding that RIS is fairly intertwined with DHCP and Active Directory for many reasons. Among them being that you don't want unauthorized DHCP servers and you don't want any old person performing a PXE boot on your network.

If you truly need to run things like that, then you may want to take a peek at Experts Exchange. They have some of the best networking experts I've ever run across and have gotten me out of a pickle or two.

[Br4tt3]

Lo pepz

I am running RIS with the usage of a Linux based DHCP function in my net. The formost important DHCP cfg for RIS (in order to work) is that

is authorized beneath the Site & Services MMC snapin (Site & Services, select the root object, from the view menu choose the "Show the services node",

choose services down in the list, then NetServices, within that list u should find the IP of the RIS box.) If not, then ur RIS machine is not registered,

authorized in DHCP correctly by Active Directory.

Dunno really how this adds up with / between Active Directory Site & Services and an external DHCP solution, but that is just the way it is..

Best Regards

ThaSausageEater...

[cluberti]

In your DHCP server, add the following options:

066 (Boot server host name): server.domain.tld

067 (Bootfile Name): \OSChooser\i386\startrom.com

Those values in your DHCP server will point the BOOTP and TFTP requests to your RIS server. Note that even if you are using a Windows DHCP server, you should still add these options to your scope.

However, unless you absolutely NEED the Cisco to be providing DHCP for your subnet, it would be better to simply enable DHCP passthrough on that router, and configure a new scope for this subnet on your Windows DHCP server. Contrary to popular belief, you do not need a DHCP server for each network subnet - and to be honest, it's easier NOT to have multiple DHCP servers on your network. Having a backup might be necessary for single point of failure issues, but for most networks a single DHCP server with multiple scopes works just as well as multiple DHCP servers for each subnet.

Edited November 22, 2005 by cluberti

[KyleJ]

The reason we wanted to have the CISCO server DHCP is so that we could bug it for the student. I can create eight different DHCP pools on the RIS server and have the CISCO relay them, but then it takes DHCP configuration and troubleshooting out of the student position. I have tried the suggestion posted; I thank you all for your input. It seams that the best scenario is to have the CISCO relay DHCP.

I have run into a second problem. When the CISCO is relaying DHCP, I can only have 2 computers booting from the RIS serve. IF I remove the router by placing the WAN cable in the switch I can boot 12 systems. In order to prepare a classroom I need to load 32 systems. I know RIS says that it can handle 75 connections, but I am not running massive system. How many RIS servers and what configuration would be best

[cluberti]

You need to make sure that your IP range for the student PC's is actually listed as a subnet in your AD Site - otherwise, the RIS server will think this is a "remote" site and limit the number of concurrent connections from IP addresses in this range.